sounds like a problem with VS2003, sometimes you just need to repair the install and the error goes away. Can happen if VS crashes or if you remove ad-ins etc. etc. Either way repairing the install may solve it, or reinstalling the add-in that you may have deleted

Hi,

Really thanks for your reply, i solved this problem when i repaired the vs .net 2003, but i have another problem in my project, the following problem is "The dependency 'ICSharpCode.SharpZipLib' could not be found.", can you please try to give some solution to this problem. Again thanks for your reply.

Thanks.

Ahh that old chestnut! with any .dll or library (reference) that you intend to use in a project it's recommendable to keep the .dll in a folder somewhere that doesnt move or add the assembly to the gac, I usually use C:\program files\ICsharpCode.SharpZipLib\thelibrary.dll (anything will do this just makes sense to me as it keeps them in an obvious place)
then when you add the reference when it looks for an updated assembly then it will find the assembly in the location it was added from. If you have already removed the reference and are still getting the error, I'd check all my code files for references (just search the whole solution) thats only if the project is not building of course. It's usually just a warning because VS2003 is looking for the file where it was originally added from to check it's build version to see if its been updated and do you a favour by adding the latest version.