The Add-in 'Win7 Taskbar Extension' failed to load or caused an exception.
Would you like to remove this Add-in?
If you choose yes, the file it was loaded from, 'C:\Users\My Account\Documents\Visual Studio 2010\Addins\Win7Taskbar.AddIn', will be renamed.
Error Message: <Unknown Error>
Error number: 80131604
I'm having trouble installing plugin since my workplace enforces My Documents to point at a default user share.
It tries installing it at \\My Documents Network Path\\Visual Studio 2010\Addins. The trouble is caused by the second "\\" in the install path.
I think it is a MS installer issue, but you can install plugin to any local folder and then copy all files to your %DOCUMENTS% manually. After all you can safely uninstall plugin from local folder.
Or you can get here http://narod.ru/disk/22247824000/Win7Taskbar Addin.zip.html archive with plugin's files, and unpack it to "Visual Studio 2010\Addins" folder.