- Close all visual studio 2010 instances.
- Open visual studio again as administrator
- Go to “Tools” > “Extension Manager”
- Uninstall NuGet
- Install NuGet again.
if you are not able to uninstall it go to:
C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\Extensions\Microsoft Corporation\NuGet Package Manager
and remove this folder.
deleting this is at your own risk!