I have an user with Windows 7 PC whose "Aero Peek to preview the desktop" stopped working all of sudden.
I ran "Troubleshooting" in Control panel, but it said "could not fix the problem" and recommend that I use "Restore" option.
BTW the check box for "Aero Peek to preview the desktop" is grayed out.
I tried on my Win7 PC, but it does not work. I ran troubleshooting/Aero and it says something about my display adapter not compatible ...