I hooked up my old computer to use as a back up, it runs on windows 98 but sound wont work, why?

I will try explain as as few words as possible if you can help diagnose the problem that would be awesome. 3 years ago I receiced a used cd rewrighter, I paid someone to install it in my computer. It worked great for a few months. One day my computer froze and wouldnt work. It was totally frozen even when I unplugged it it would load, than freeze. One day last week, I unplugged the cd wrighter I had installed and turned it on, it worked almost perfect since! The only thing is now there is no sound at all. When I try adjust the volume there is no volume control to adjust, Even Wehn I go to start menu than accessories than entertertainmeent than click on volum control, nothing happens, it doesnt even try load the sound control, it is almost lke it was never there!