Error while opening a dot net solution after running dotnet cleaning tool

[EZsolutions.association]

Hi,

I have a vb.net solution project for a web service. Our admin
run, .net cleaning tool on the development server and after that i am
not able to open the solution file. When i double click the solution
file i am getting the message - "C:\Projects\abc.vbproj can not be
opened because its project type(.vbproj) is not supported by this
version of the application. To open it, please use a version that
supports this type of projrct"

This web service solution was developed using studio 2005 and still i
have studio 2005 installed on my machine. After running the cleaning
tool, My admin has installed .net framework back but still i am
getting the error. Is any one has experienced this before? Any
suggestion or idea to get it back working?

Thanks,