When this happened to me, I spent a little time searching, and found the above utility. It did nothing and claimed that my video card (a Radeon 7970), which used to display Aero perfectly, isn't capable of supporting Aero.
Here's what I tried:
- Many reboots: didn't help
- Updated the graphics drivers: didn't help. The repair utility still claimed that my graphics card doesn't support Aero
- Installed all updated, which I was behind on: This didn't help either
- Tried killing all running process that I could. No go.
- Uninstalled a few applications I had installed in the past 2 days, still no go
I should have made note of the KB update number(s), but at this point I was pretty frustrated, thinking I'd have to restore a drive image. If any one knows the KB numbers of the updates installed with the IE 10 preview, please let me know.
Summary: IE 10 preview and associated updates can cause Aero to stop working.
Edit 2012-11-19: Thanks, Dean for the KB update number: KB2670838.