Windows 7: Stereo Mix regedit help!

I dont have sound after doing a regedit tweak to get stereo mix up, which did work but now i have no sound, heres a link to what i did, Instruction for Enable Sigmatel Stereo-Mix in All dell PC & Laptop...in Windows XP...
i still can hear sound tho through my headset but not how i normally do on my monitor and i tried testing the sound of my speakers and i get a popup saying, "device in use, the device is being used by another application, please close any devices that are playing audio to this device and then try again"
please someone help!! ty.

Quick solution:
Do a System Restore to a point before you made the registry changes.

There may be a way to get the "Speakers" to work at the same time as the "Stereo Mix", but as you have read in that link (the replies at the bottom), that fix caused your symptoms for other people. That fix works for some but not for others.

Do the System Restore, then try a different solution.

im working on it i hope someone know tho out there keep them coming