I want to free a Visual Studio 2010 Professional license, so my company can use it on another computer, by removing it from "Add/Remove Programs". But I fear it can damage my Ultimate installation. What is the safest way of doing that?
Visual Studio does not use activation, so you would be fine with having both versions inatalled.
Yes you can!
I had two versions of VS2012 installed that I could see clearly in Control Panel's Program Features:
A year ago, when I installed Ultimate 2012, I don't know why MS had them be installed side-by-side, rather than just upgrading VS Premium 2012.
After uninstalling VS Premium 2012 (via their uninstall tool), VS Ultimate 2012 still worked for me. I also saw reclaimed hard drive space, though not as much as I thought I should have seen.
Hope this helps! Good question.