I had to resort to using a key generator in order to continue using a product I'd legally purchased from Adobe. I had a lot of stability problems with my computer a few years ago and had to reinstall several times - sometimes I was able to deactivate photoshop, but a couple of times it was a crash and reinstall. I think it was because I redid the RAID array that the activation system believed it was a different HD and/or computer.
Reactivation was painless with Microsoft, I called them and confirmed (truthfully) that I was not installing a duplicate copy of Windows onto another machine, it was a fresh install over an old crashed copy. Took about 5 minutes in total. Adobe was another matter completely, I was on hold for HOURS to their phone activation system, TWICE. I gave up trying to get through, then someone sent me a keygen and I haven't had to bother with Adobe activation since.
It's ridiculous that I have to do this for a product I have legally purchased.