Windows Update Error

Today I faced an error when trying to install few updates for Windows. The message Windows was showing was “Windows update encountered an unknown error.”. So it was not helpful in resolving the issue.

This is happening due to either update not getting downloaded properly, getting corrupt while downloading, space issues in your hard disk, errors while applying updates, etc.

To my satisfaction one thing I did, fixed the issue. If you are also getting similar error I recommend you to first browse to your SoftwareDistribution folder inside Windows installation folder. For example I found it in “C:\Windows\SoftwareDistribution”.

Then delete all the folders in the folder (make sure the Windows Update is closed before doing this) and restart your computer.

After making sure your Windows installation partition is having enough free space (about 1 GB) try running Windows Update again. This time the updates will get installed successfully.

Error Installing Windows 7

Recently I tried installing Windows 7 64 bit version in to my HP Pavilion laptop, and I continuously got a problem while installing.

Installer was generating a blue screen with a message Page_Fault_in_NonPaged_Area referring to the file “wimfsf.sys” after coping files and showing the new Windows logo for about 10 seconds.

Since it is mentioning about a page fault and also I am trying with a 64 bit version of Windows I thought this is due to a problem related to hardware of my laptop, so I tried many alterations which included things like, flashing BIOS to various versions including new and old, plugging memory in different ways, installing other OSs to try setup Windows from within them, but nothing helped me to sort the issue except replacing the DVD.

Yes indeed, it was an issue with the installation media (DVD), if you also get a similar error when installing Windows 7, I suggest you to first try installing with a different media.

If you still get an error then try running Windows 7 Upgrade Advisor which can be downloaded from Microsoft. This will analyze your machine and will report you the compatibility details.

Also,

- updating your BIOS to the latest version,

- installing with only one memory module when you are having more,

- disabling special processor (virtualization) and memory (memory caching) functionalities,

- changing hard disk drive options,

will help you getting Windows installed successfully.

SQL Server Reporting Services Error - The report server cannot open a connection to the report server database. A connection to the database is required for all requests and processing. (rsReportServerDatabaseUnavailable)

Recently in one of my virtual servers I got the above error when trying to open the SQL Server Reporting Services (SSRS).

If this is happening to you I recommend checking the following things in your server.

 

1. Remote Connections in SQL Server.

Go to Start –> All Programs –> Microsoft SQL Server 200x –> Configuration Tools and open SQL Server Configuration Manager.

Now check whether the TCP/IP and Named Pipes are enabled in the 3 Protocol sections.

If they are disabled then enable them then check whether the remote connections are enabled using the SQL Server Management Studio by right clicking on the SQL Server (Parent node in the Object Explorer) and selecting properties.

Then go to the Connections and make sure that the Allow remote connections to this server checkbox is checked.

Then restart the SQL Server Service using the SQL Server Services section in the SQL Server Configuration Manager or by going to the machine services by Start –> Administrative Tools –> Services.

 

2. Check the SSRS Service Account.

Go to Start –> All Programs –> Microsoft SQL Server 200x –> Configuration Tools and open Reporting Services Configuration Manager. Then click on the Service Account section and verify its details. If you are not sure about the details it’s always good to re-enter them since there is nothing to loose.

3. Check the SSRS Database and Credentials.

Click the Database section and see whether all details are correct. This is very important since SSRS need to get connected to its SQL database to function properly. Pay good attention to validate the SQL Server Name, verify the database mentioned under Database Name exists in the specified SQL Server. If you are not sure of the existing settings just click on the Change Database button and it will open a wizard to step through.

If you already have reports in the SSRS then always try to Choose an existing report server database before Creating a new report server database since when you create a new database you will loose existing customizations you might have.

Then go to the bottom section to see the Credentials provided are correct. I am used to validate these by opening the management studio and trying to connect using the provided account. After validating the account using the management studio, to be in the safe side you can set those settings using the Change Credentials button.

 

4. Check your Firewall.

If the you have enabled a firewall such as Windows Firewall or a 3rd party firewall it might be blocking the functionalities required. Just try switching off the firewall, if that solves then try creating a rule for the firewall to authorize the required connections.

 

Hope this helps to correct the error, if not let me know some times I may be able to help.

.Net Nullable Types

A variable of a nullable type can be used to store the normal range of values allowed by the underlying data type plus the Null. Nullable types are instances of System.Nullable.

Since reference types already supports Null, nullable types represent value type variables which supports null.

For example Nullable<bool> (or spoken like nullable of bool) can be used to store true, false and null.

There are two ways to declare a nullable variable.

Method 1

int? i; // Declaring
i = null; // Initializing

int? i = 4; // Declariong and initializing

Method 2

Nullable<int> a; // Declaring
a = 4; // Initializing

Nullable<int> a = null; // Declariong and initializing

As you see above assigning values to a nullable is same as for a normal variable. But when retrieving the value you need to be little careful.

Method 1 – Using GetValueOrDefault

GetValueOrDefault property is available for nullable variables. If the variable is null it will get the default value for the type otherwise the actual value it contains.

textBox1.Text += "Value of i - " + i.GetValueOrDefault();

Method 2 – Using variable.Value

When you are going to retrieve the value inside the variable using .Value be careful to first check whether there is actually a value in the variable, otherwise .Net will generate an InvalidOperationException with a description of “Nullable object must have a value”.

// \r\n is used to insert a new line.
if (i == null)
    textBox1.Text += "\r\n" + "i is Null";
else
    textBox1.Text += "\r\n" + "i is - " + i.Value;

or

// Environment.NewLine is equal to placing a new line or \r\n.
if (a.HasValue)
    textBox1.Text += Environment.NewLine + "a has - " + a.Value;
else
    textBox1.Text += Environment.NewLine + "a has Null";

The full code would look like the following.

1. // Declaring Method 1
2. int? i; // Declaring
3. i = null; // Initializing
4. //int? i = 4; // Declariong and initializing
6. // Get value using GetValueOrDefault().
7. textBox1.Text += "Value of i - " + i.GetValueOrDefault();
9. // \r\n is used to insert a new line.
10. if (i == null)
11.     textBox1.Text += "\r\n" + "i is Null";
12. else
13.     textBox1.Text += "\r\n" + "i is - " + i.Value;
15. // Declaring Method 2
16. //Nullable<int> a; // Declaring
17. //a = 4; // Initializing
18. Nullable<int> a = 4; // Declariong and initializing
20. // Environment.NewLine is equal to placing a new line or \r\n.
21. if (a.HasValue)
22.     textBox1.Text += Environment.NewLine + "a has - " + a.Value;
23. else
24.     textBox1.Text += Environment.NewLine + "a has Null";

The output would be,

Value of i - 0
i is Null
a has – 4

You could use the ?? operator to assign the default value for a non nullable variable while the nullable contains null as the current value.

int? Null_X = null;
int NonNull_y = Null_X ?? -1;

Features of Search Engines

How many of you know that common and popular search engines like Google and Bing are providing many other functionalities than searching?

Yes it is true there are many functionalities within them that most of us don’t know.

Following are some features, you can try these out by typing the italic text in your favorite search engine.

1. Finding the date and the time of a place. – “Time Sri Lanka”, “time Melbourne”
2. Checking spelling of words. – “Cheking”, ”mathmatics”
3. Finding results of arithmetic. – “(25*34)+78”, “2**5”
4. Finding the weather if a place. – “Weather Colombo”, “weather Changi”
5. Finding the populations of countries or popular cities. – “Population UK”, “population Sri Lanka”
6. Converting units. – “12.5km in Meters”, “3km in inches”
7. Stock details. – “MSFT”, “AAPL”
8. Find similar word (Synonyms). – “~Cooking”, “~hot drinks”
9. Finding currency values. – “1 GBP in AUD”, “89.34 AUD in USD”
10. Finding maps. – “New York Map”, “Sydney map”
11. Finding definitions of words. – “Define Computer”, “define language”
12. Other than above you can find about Books, Movies, Air Line Schedules etc. But they are widely for other countries like UK, US.

While searching you can use special characters like wild cards, concatenate, subtract to help while searching. Try them out to find the results by your own.

Business Data Catalog - BDC

As of Microsoft, Business Data Catalog is a new feature introduced with SharePoint 2007 which can be used to integrate business data from backend server {Line Of Business (LOB)} applications.

There are few good articles I found in the following web sites if you are interested to read more.

• http://msdn.microsoft.com/en-us/library/ms563661.aspx
• BDC Purpose and Technical Architecture
• Application Definition File (ADF) and its Development
• Developing an ADF to Connect to Web Services
• Consuming Business Data through Web Parts and SharePoint Lists
• Implementing Enterprise Search with Business Data
• Integrating User Profiles with Business Data
• Working with the BDC Object Model
• Using Actions in BDC
• http://blah.winsmarts.com/2007-4-SharePoint_2007__BDC_-_The_Business_Data_Catalog.aspx

How to Read and Write Text

Reading and writing to text files had been made easy by .Net.

Following code will create a text file and insert 2 lines to it and will then read it and display.

1. // System.IO is required for file handling.
2. using System.IO;

1. // Creating a stream writer object.
2. // @ is used before the string to avoid the string getting broken by the /.
3. StreamWriter stWriter = new StreamWriter(@"C:\Backup\File.txt");
5. // Writing into the file.
6. stWriter.Write("It is now ");
7. stWriter.WriteLine(DateTime.Now);
8. stWriter.WriteLine("The End");
10. // Closing the file.
11. stWriter.Close();
13. // Reading the file.
14. // Checking the availability of the file.
15. if (File.Exists(@"C:\Backup\File.txt"))
16. {
17.     // Without using the @, \\ also can be used to represent \ inside of a string.
18.     using (StreamReader stReader = File.OpenText("C:\\Backup\\File.txt"))
19.     {
20.         // Temporary variable.
21.         string str = "";
22.         while ((str = stReader.ReadLine()) != null)
23.         {
24.             // Assigning to a label.
25.             label1.Text += str + "\n";
26.         }
27.     }
28. }
29. else
30.     MessageBox.Show("Error, File cannot be found.");

SharePoint Page Types

Do you know in SharePoint there are two types of pages?

In a SharePoint site each page you see is either a ghosted page or an unghosted page.

Ghosted (Uncustomized) Pages

These are the pages stored in the severs file system but not in the database. The other important thing is these files are common to all the site collections within the SharePoint server and are generally based on the "out of the box" site definition templates. Basically they are working as template files. Ghosted pages are faster since ASP.NET parser will be used to parse them and as you might know ASP.NET parser will compile the page into an assembly on the first time it is rendered, on subsequent executions the compilation is skipped since the assembly is already there.

When ghosted pages are modified by SharePoint designer then they will become unghosted pages, and then SharePoint will start using that file in the future not the file stored in the file system. A common example for this would be the “default.master” file on the “C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\Global“.

Unghosted (Customized) Pages

These are the pages which are stored on the database. Unghosted pages are specific to the SharePoint web site the page is in. If you change these files it will not affect any other site in the same SharePoint server. Unghosted pages will be parsed by the safemode parser which will not compile the pages. The only dynamic code allowed is server-side controls that are marked safe (Safe Controls, Trusted Controls).

Why Ghosting?

This allows SharePoint to,

• Increase it’s performance by enabling caching the main site template into memory and then apply the changes that are stored in the database for the specific file.
• Increases security by not allowing unghosted pages to run code so an attacker who injects code will not be able to crash your server.

Finding the IP Address of the Email Sender

Recently I was bit curios to find out whether we can find the IP address of the sender in an email. After doing some web searching I found interesting sites which describes what needs to be done.

If you like to find out the way to do this please visit and see.

http://www.johnru.com/active-whois/trace-email.html

http://aruljohn.com/info/howtofindipaddress/

Protect HTML Files

Recently I came up with a requirement to protect a website which was created using HTML.

When searching over the internet a team member of mine found a nice software called HTML Guard.

This software is encoding the source of the site so the users will not be able to see the code behind the site. Using this tool you can even block a site to a particular domain. Even the site is downloaded it will not properly run.

The best thing is this has a free version so we can use the full set of features without paying (A small message will come on the top right corner saying the site is encoded by using the tool).

This software is by WulfSoft, thanks guys you have done a good job.

Try out yourself and see.

http://www.htmlguard.com/

Reading and Writing to Excel Files

Even though I posted similar 2 articles in 2008, the code of that article was having few errors. So thought to put more complete post on this.

The code will read an Excel file using an OleDbConnection and will write the same data back to another Excel file. This will explain how to read and write to Excel files. One thing to remember when running this code is to make sure the source Excel file is open. Otherwise you will get an error similar to “External table is not in the expected format.”

Also note that there are few connection string parameters you can use while opening Excel files.

HDR = Yes – Use when first row contains column headers.

HDR = No  - Use when first row contains data.

Excel xx.x – Use the following Table as a guide.

Parameter Value	Excel Version
Excel 12.0	Excel 2007 (Released in 2007)
Excel 11.0	Excel 2003 (Released in 2003)
Excel 10.0	Excel XP (Released in 2001)
Excel 9.0	Excel 2000 (Released in 1999)
Excel 8.0	Excel 97 (Released in 1997)

 

IMEX=1 – Use this when you want to treat all your data in the file as text.

For example - >

Extended Properties="Excel 12.0 Xml;HDR=YES;IMEX=1";

To make the code to work properly you need to refer the Microsoft.Office.Interop.Excel assembly by adding a reference to your project.

1. using System;
2. using System.Data;
3. using System.Windows.Forms;
4. using System.Data.OleDb;
5. using Microsoft.Office.Interop.Excel;
7. namespace TestApp
8. {
9.     public partial class Form1 : Form
10.     {
11.         public Form1()
12.         {
13.             InitializeComponent();
14.         }
16.         private void button1_Click(object sender, EventArgs e)
17.         {
18.             openFileDialog1.ShowDialog();
19.             // Create an OLEDBConnection to connect to the Excel file.
20.             // I'm getting the required file by using a file dialog.
21.             // The @ symbol makes the string to contain any special characters inside the string without breaking the string.
22.             OleDbConnection dbConnection = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + openFileDialog1.FileName.ToString() + @";Extended Properties=""Excel 8.0;HDR=Yes;""");
23.             // Open the connection.
24.             dbConnection.Open();
25.             // Create a command object to work on the data.
26.             // Note that I have given the sheet name as [Sheet1$] to retrieve data from that named sheet in the particular Excel file.
27.             OleDbCommand dbCommand = new OleDbCommand("SELECT * FROM [Sheet1$]", dbConnection);
28.             // Creating a data reader to read data.
29.             OleDbDataReader dbReader = dbCommand.ExecuteReader();
30.             // If needed you can get the position of any column (e.g. Age), this will only work if you use HDR=Yes.
31.             int SearchingItem = dbReader.GetOrdinal("Age");
33.             // Create the Excel Application object.
34.             ApplicationClass ExcelApp = new ApplicationClass();
35.             // Set the visibility of the application.
36.             ExcelApp.Visible = true;
37.             // Create a new Excel Workbook.
38.             Workbook ExcelWorkbook = ExcelApp.Workbooks.Add(Type.Missing);
39.             // Create a new Excel Sheet.
40.             Worksheet ExcelSheet = (Worksheet)ExcelWorkbook.Sheets.Add(ExcelWorkbook.Sheets.get_Item(1), Type.Missing, 1, XlSheetType.xlWorksheet);
41.             // Will keep the current row index. This should start from 1 since the first row is 1.
42.             int CurrentRowIndex = 1;
43.             try
44.             {
45.                 // Read through the data.
46.                 while (dbReader.Read())
47.                 {
48.                     // Traverse through all the data columns.
49.                     for (int i = 0; i < dbReader.VisibleFieldCount; i++)
50.                     {
51.                         ExcelSheet.Cells[CurrentRowIndex, i + 1] = dbReader.GetValue(i);
52.                     }
53.                     CurrentRowIndex++;
54.                 }
55.                 // Save the Excel sheet.
56.                 // The @ symbol makes the string to contain any special characters inside the string without breaking the string.
57.                 ExcelApp.Save(@"C:\Projects\Ex.xls");
58.             }
59.             catch (Exception ex)
60.             {
61.                 MessageBox.Show(ex.ToString());
62.             }
63.         }
64.     }
65. }
66. 
    

Project has Stopped Working

If you create a .NET application to use SQL CE database when you try to run your application on a Windows Vista or Windows 7 machine you might get an error saying your application did stop working, and the error details might show that your are having a problem with System.Data.SQLServerCE.

The reason for this is that your system is not having the SQL Server CE runtime in your machine. To fix it what you need to do is to install the Microsoft SQL Server Compact 3.5 Service Pack 1 on your system. You can download it from the following Microsoft link.

http://www.microsoft.com/downloads/details.aspx?FamilyId=DC614AEE-7E1C-4881-9C32-3A6CE53384D9&displaylang=en