This is the third time I have had the following problem develop on my computer and I am hoping someone has a suggestion on how to prevent it from happening again.

I have an HP desktop running Windows XP Home. The problems begins with a distortion of the sound, so that when XP boots up initially the "Welcome" sound sounds like it is playing under water. Eventually the distortion effects my dial-up modem tones and gets so bad that I am no longer able to get connected to the Internet through my dial-up modem.

Nothing shows up in the control panel as having a problem and all system checks  come back as properly operating. Removing and re-installing the sound driver doesn't resolve the problem.

Once this happens I find that I am unable to use Windows Restore, it seemingly goes through it's cycle but when it re-boots the system, a message comes up that says "system was not able to be restored to this restore point, no changes were made to your system." All restore points lead to this same message.

Also, I cannot use the Windows XP installation disk "repair" option either, because it abnormally terminates with a memory exception error that renders the operating system toast, at which point I have to do a fresh install.

This is the third time this problem has occurred. After a fresh install, everything works fine for about 2 months, until the sound warbling starts all over again.

Any suggestions would be greatly appreciated?

Thanks.

This looks more like a hardware problem. The soundchip on the motherboard may be going bad.
Possible software solutions would be a bios update or an update for the motherboard or soundchip drivers to solve a conflict with other software. Check the HP web site for those possibilities.
If no updates exist, you could disable the sound chip and install a sound card to solve a possible hardware problem.

Sounds like a recurring virus to me. Just my thought but that's what I would look for.

Check out this site I believe that you need to update your drivers
http://driveragent.com