[soapbox]
Okay, your first problem was assuming you had to reinstall windows to get the soundcard to work. I have friends that reinstall windows anytime that something doesn't work, and I understand that the windows mantra has become reinstall, reinstall, reinstall. Still, for my own systems (DOS 3.2-6.22, win3.0, 3.1, 3.11, 98, 98SE, ME, and 2000), I have yet to remove and reinstall windows for any problem (knock on wood). While it's an "easy" fix to most problems, it's just a bad habit that MS and other companies don't seem to mind promoting. Yes, I've had nearly 20 years on IBM-style hardware (i'm only 30, btw), but that doesn't excuse people from not spending a little more time trying to actually fix a problem.
[/soapbox]
You simply need to use your bootdisk (you have one, correct?) and boot into debian that way. Then run 'lilo' as
root to reinstall your previous boot loader settings. (Windows overwrites them when installing, of course.) You can also use your debian disks as rescue disks (depending on your version) and enter debian that way.
This is assuming you are using lilo in the first place. If you use grub (i don't, I'm old-fashioned about that, too), here is a place you can learn more.
http://www.gnu.org/manual/grub/html_mono/grub.html
It's the same idea, however. You should just have to tell grub to write it's information to the MBR. If your windows box is 2000 (XP?), you're going to want to use the windows boot loader to control the booting. In that case, simply tell the windows bootloader which partitions to access.
Again, don't be so hasty to reinstall a complete OS (windows or linux), especially in a corporate setting, unless you have good reason to. Doing so only numbs your brain to otherwise easy fixes.