Robert Rietvelt wrote:
... if you haven't got a newer version. If you have a licence for lets say 2014/2015 or 2017, you can't reinstall 2011. The licence is valid for the latest version you owe.
That is correct if you upgraded from a previous version, not if you purchased a full new version - which most people admittedly don't do, but I just wanted to get that straight.
To OP: when you need to reinstall Studio, you first need to return your license (within Studio). If you didn't do that (for example when your pc crashes, or you didn't know), you may request SDL to re-issue you a license. You have to log in to your SDL account and request a license.