I had used Revo to Uninstall WinAmp, so THAT advice gave no progress.I tried various things IN VAIN.
Then a peculiar habit I have came to my aid. It may seem a tedious story, but it was my salvation (this time) and has been that several times in the past.
I clone my system every week - to two other HDDs which I can experiment on SAFELY as they are disposable. I also clone to one of three partitions on a larger HDD, so that I always have a copy of my system as it was one, two and three weeks ago. It turns out that only on my oldest clone did WinAmp still work well, so I reverted my running system to that one, and have been using WinAmp successfully since. I have NO idea what went wrong with WinAmp, but now I no longer NEED to know, as the problem has been by-passed. I would LIKE to know, but have no chance of finding out as I have replaced the 'faulty' clones with 'viable' ones.
It is possible that some residual files when uninstalling WinAmp are not fully deleted from your PC, that's why it won't open anymore.
Try performing a full uninstall by downloading Revo Uninstaller. Uninstall WinAmp using this tool, next select the Advanced mode to scan and delete all leftovers.
Restart your PC, then reinstall WinAmp.
Hope this will work.