Help - audio disappeared!

[jdoe]

I have Audacity 1.2.6 installed on an Eee netbook... Audacity had been working just fine, and I was having no problems with the Audio.

I had YouTube up, and wanted to record something - so I was using Audacity. It didn't seem to be recording at a very "loud" level, so I started playing with settings...

I was in the Edit > Preferences menu, playing around with the devices, and the Channels...

I only have 2 devices (for both drop down boxes) - Microsoft Sound Mapper and Realtek HD Audio. (I have currently reset both of these to the Miscrosoft option, I'm not 100% sure if this was the default).

I have tons of channels - I had tried to set it to stereo (and have since reset it to mono).

During this, my computer had STOPPED outputting ANY AND ALL sounds. No system sounds, no playing MP3s, no Youtube sounds - everything is gone!

I have checked everywhere I can find for volume/muted, and that seems fine. I've checked random things in the control settings and dxdiag, and everything seems to be reporting back as fine. Also tried a reboot, no luck though.

But I can't hear anything....

Is this a known problem? Any ideas how I can get the sound working again?

Thanks for any help, I've tried searching - but not sure what to target (getting tons of random hits for things like "no audio")

Thanks,
-Jen

[jdoe]

Quick followup -

I fixed this by using a Microsoft system restore point. I've never done this before, so I'm not sure what exactly gets changed (some other files I downloaded today are still present, yay!) -- but it did bring the sound back!

I'd still love to understand what I did wrong and how it could have been fixed/avoided, so that I don't screw it up again in the future!

Thanks!
-jen