27. June 2013 04:56
If for whatever reason your dev environment turned up to be behind of a web proxy server (for instance, if you work with the cloud hosted TFS), you won't be able to check-in/check-out without proper proxy settings in your Visual Studio. Unfortunately, VS doesn't use system settings. There are few "unofficial" methods how to do this. One of them is to manually add some settings to your devenv.exe.config file but I prefer do not touch system settings in such way especially because there is another one and more natural.
In your Visual Studio 2012 environment open menu Tools -> Extensions and Updates and choose Updates – > Product Updates on the left. If proxy wasn't setup yet, VS will prompt you to enter required information and you will be able to work with TFS. As a side effect, your environment will be able to check updates automatically. So this is 2-in-1 suggestion .