Why did it stop working to begin with?
As long as you keep a copy (USB stick?) of those folders, just in case, you really don't have much to loose, if it isn't functioning now.
I would do a new install, then replace the new folders with the ones you still have copies of. If this is on the same machine as the original installation, you might not even have a licence issue as the MAC of the NIC will still be the same.
It might take a few attempts to make this works as it may not require replacement of all of the directories, and doing so may cause other issues.