Having trouble upgrading your Nuget Package Manager? If you get the error described in Microsoft’s explanation, their advice isn’t enough. After uninstalling it from the control panel, it is still present (yup!) and still won’t let you upgrade. “Zombie like it still exerts a malign influence even after death…”
Here’s what you need Close down Visual Studio. Look for C:Program Files (x86)Microsoft Visual Studio 10.0Common7IDEExtensionsMicrosoft CorporationNuGet Package Manager
and you’ll see the folder for the older Nuget version; something like 1.5.20902.9026. Just delete it. Now you can upgrade. Simples!