You had a soundcard going - changed to another distro - distro didn't take so you changed back - soundcard didn't go.
Now, the way you wrote it, it looks like you've changed from windows to ubuntu then back to windows - perhaps you tried a dual boot but Ubuntu didn't take?
It is unlikely that ubuntu would have fiddled the windows settings, since it would be doing everything in different partitions... however, if you were not careful during the install process (like at the partitioning stage) then vital data could have been lost. Remember, windows can put data anywhere!
Cleaning and repartitioning ntfs drives is problematical - so much so that many members here just buy a new hard drive for linux - and the defrag process for vfat based systems (win98) needs to be done from a dos boot to be certain.
To get your soundcard back, probably best to try reinstalling it's drivers. Or, simply(?) reinstalling the OS you want.
If, however, you did a clean install of ubuntu (no other OS) and then a clean reinstall back to the start, then Ubuntu is completely innocent. Look hard at the reinstall.
Now: I see from the sidebar that you have Yoper 2.0 (2.1 is out...) listed as your distro? This "changing OS losing sound" seems often associated with yoper. It seems that yoper is very specialised and changing things around can make for lots of work. This is the price of all that power and speed in a small (single iso) package!
If it is yoper that cannot find the card, as opposed to windows, then the fastest fix would be to reinstall yoper. The install is very fast, probably faster than tracking down the fault to correct it.
Googling this problem for yoper produces lots of promising links to http:\\www.yoper.com
... but I havn't been able to connect. Odd for an active distro.
BTW: "gfx" stands for "graphics" - and your card is listed as a graphics accelerator card. Getting sound out of it would be difficult anyway. Try doing lspci and showing us what *does* happen.