Sounds from Internet Sources not Working

I recently had to do battle with a fake antivirus scanner and was able to beat it off my computer.  However, right after finally removing the fake program I lost all sounds that came from an internet source.  I have gone to google and tried several suggestions from the "No Internet Sound", all to no avail.  The other problem, most likely secondary to the first, is that I have lost the Volume Control icon from the system tray at the bottom right of my screen.  Coupled with this I am unable to change the volume of the computer through my keyboard (Fn + PgUp/PgDn), so that if I want to change the volume I have to manually go through the start menu to find the volume control program.

I am currently working off of a Gateway notebook running Windows XP SP3.  I am currently able to play videos and mp3 files on my computer and have sound for those files.  However, I have lost 100% of the sounds from my IE 7.  According to one messenger chat service, my computer does not have audio input capability.  I don't know if that will help.  But any help that you may give me I would greatly appreciate it.

P.S.  I have tried the missing.reg trick and it does not seem to have worked.

Same thing in Firefox?

I'm sorry that it took me so long to see this reply.  I don't have Firefox on the computer at all, never have.  And now that I've gone back through my computer again, I have realized that I not only lost the sounds on the internet but also the sounds for the computer itself.  Yet it will still play mp3, avi, mp4, mkv, etc. files.