I had the same problem and it was due to a windows update that came out on the 26th. I went here and followed the instructions to uninstall and no more problems.
Issue 1 was related to the installation of KB973879
Issue 2 was related to the installation of KB972036
In order to resolve both issues, the solution is to boot into Safe Mode and uninstall the updates. If that is not an option, System Restore to a date prior to August 25, 2009 is suggested.
Solution 1 – Uninstall the Updates in Safe Mode
1. Start the system in safe mode by pressing F8 repeatedly during the start-up process.
2. Choose “Safe Mode” from the list of advanced start-up options.
3. Click Start, and then click Control Panel.
4. Click Uninstall a Program under the Programs section.
5. In the Tasks list in the left navigation area, click View Installed Updates.
6. Click the entry for either KB973879 or KB972036 (or both if found) and then click Uninstall.
7. Click “Yes” when you are prompted to confirm the uninstallation.
8. Restart the system when you are prompted.