After installing the SharePoint Server when you try to start the search service you might end up with the following error.
An unhandled exception occurred in the user interface.Exception Information: OSearch (Administrator)
or
An unhandled exception occurred in the user interface.Exception Information: OSearch (UserName)
If this comes don’t panic, what you need to do is when providing the username provide it with the full domain name. For example Domain.Local\Administrator.
You can find the Microsoft knowledge base article here.