Visual C# "Unable to Open Project"

I've been using Microsoft Visual C# 2008 Express Edition for the past two years. I made some very slight changes to a single project last night and now want to open the project and make a couple of changes. Out of the blue I'm getting the following message when I try to load the project:

Unable to read the project file 'myfile.csproj' Could not load file or assembly 'sorttbls.nlp' or one of its dependencies. Incorrect function. (Exception from HRESULT: 0x80070001)

The above message stops me from accessing any part of the project. (I am able to load the source code in Notepad so at least I don't have to worry about losing the code altogether). This error does not seem to be associated to any recent changes to my code as I run into this error when open up a simple console project or try to create a new project. What happened? (Did my computer get infected with a virus?) How do I get past this?

Thanks!

May be you can use following source

sorttbls.nlp Problem

According to which you can uninstall and install .Net 2 or 3.5 and perform Reboot

If you have ATI card above link might solve your problem