We could help you if you have us either a motherboard model or a PC model (if it's branded, like HP or Medion).
It is quite strange that your sound drivers were lost after formatting a spare HDD. This leads me to conclude that you can reinstall sound drivers without downloading them from the Web. In Device Manager, select Sound, video and game controllers. Then, there should be a symbol of device not installed, normally named as audio controller or smth like that. Right-click on it, choose Properties-->Driver tab, then Update driver. A Welcome to the Upgrade Device Wizard will start. Click Next. By default, Search for suitable driver is enabled. Click Next. Windows will look for necessary files and most probably it'll find what it needs (because if you used drivers, e.g. played music with this Windows, they must be in place). If that doesn't help, we'll need some additional info about hardware.
Updated: It's quite possible that you're using something from Creative Labs. You can try their online tool to detect a sound card. If it's really Creative, the drivers will be supplied.
Go to
http://www.creative.com/language.asp...wnloads/su.asp
Please note that IE 5.5 or higher is required (it doesn't support Firefox, unfortunately).
Choose only Essential and Critical Updates to install. The Recommended ones will load your system with well over 100 megs of staff you most definitely don't need (just my opinion, anyways).