After you have installed Visual Studio, it exists on your root folder.
You could find it in the following path.
in your command prompt
You should type cd \\<your Visual Studio>\Common7\IDE\VWDExpress. run
1."VWDExpress.exe /resetaddin" => close VS2008
2. run " VWDExpress.exe /resetskippkgs" => close VS2008
3. run " VWDExpress.exe /resetsettings" => close VS2008
4. close prompt
5. run VWD2008 normal (under VISTA with "RUN AS Administrator"
.