Error installing NuGet

Issue:
I was trying to install NuGet, and I got this error.

Then I realized that I have installed NuGet before. When I tried to click on the "Update" button for the NuGet, I got the same error too.
After doing some research, finally I have found this is a known issue, and it's documented in NuGet  docs.
I just installed the Visual Studio 2010 SP1 hotfix and the problem is solved!

Just go here to solve the problem - Known issues with NuGet.