Usually when system restore starts doing this, it will continue, and only create restore points which are of no use, try to repair it, if it does not change anything, you need to turn system restore off, reboot, and then turn system restore on, create a restore point and try it 24 hours or so later. You could also look at reducing the amount of space system restore uses, this will mean it clears older restore points to make room to create new ones more often
1. Click Start, click Run, type %windir%\inf and press enter
2. Locate the Sr.inf file, right-click the file, and then click Install.
3. In the Files Needed dialog box, click Browse. Locate the Sr.sy_ file in the i386 folder of the Windows XP CD, click the file, and then click Open.
4. When the installation is completed, restart your computer.
As the computer reboots, keep tapping F8 during the initial start-up until you get options, select Safe Mode with a Command Prompt then press enter.
2. Log on to your computer with an administrator account or with an account that has administrator credentials.
3. Type the following command at a command prompt, and then press ENTER:
%systemroot%\system32\restore\rstrui.exe
4. Follow the instructions that appear on the screen to restore your computer to an earlier state.
Look for the most recent system checkpoint created before the errors to restore from
As to the sound, you can re-install the software, either from the CD or from the manufacturer's site