There is a lot of discussion about Mandrake and AC97 on-board sound in this forum. I'd suggest searching the forum for the combination of these words and browsing around a bit.
It seems to me that if you can get ALSA installed/configured and set up to load the snd-intel8x0 driver you have an excellent chance of success with an AC97.
Otherwise the m/b manufacturer may supply a linux driver in some form. Or maybe Mandrake has a update/fix on its site.
But if you can't find a precompiled package to fix the problem, and are not happy tinkering with your computer, the easiest and almost certainly the most cost-effective thing is to buy a cheap soundcard of a well-known brand, plug it in, and disable on-board sound in the BIOS
Or you can switch your distribution. The presently highly up-to-date Knoppix/Debian live CD will almost certainly work with the "knoppix alsa" boot parameter. But is it worth ditching your experience with your current distro?