Alcohol 120% is good Windows software. It does three things:
Got some SafeDisc bad blocks on your CD? No problem. Got some funky SecureROM 4.8 spiral tracks? No problem. Rip the disc to your hard drive, then either mount it with their emulator or burn it to CD-R.
Mostly I use Alcohol 120% to rip the games I buy so I don't have to have the physical disc in the drive to play. No more downloading scary cracks. I also rip all discs before I ever mount them; the virtual device is much faster than the physical.
Obviously Alcohol 120% enables piracy. I haven't seen their MDS files (ISOs with the out-of-spec data) turn up on file sharing networks, but that can't be far away. But I hope they're not tarred with the piracy brush; the software is great for legitimate use, too. Fair use has a posse.
Daemon Tools is a free hackerware predecessor. Alcohol 120% is a polished commercial product.