Jude -- I would recommend going to SoundBlaster's web site to see if they have a download that will reinstate your son's PC prior to the s3 savage install.
Windows ME is a very good OS. I have it on one of my systems. You should be fine with it. However, once you take care of the bios problem, it would probably behoove you to back up all the important data files, then format the disk and reload the OS.
Reloading the OS is quite easy -- especially if your son's PC was purchased with pre-installed software. The manufacturer will have provided recovery CDs. Piece of cake. Of course, you will have to reload all of the application software that was added later.
A fresh start will do wonders.
A good site to check for help and info is
http://www.cnet.com
Hope this helps...dmp