This solution is probably valid for only a handful of people.
After the latest Windows 7 updates were applied, I found my computer took over 10 minutes to boot into Windows. It would hang at the “Starting Windows” screen for ages (between 12 and 15 minutes).
After (far too much) troubleshooting, the problem turned out to be that I had left an SD card formatted for the Raspberry Pi in the SD Card reader. Removing the card restored boot time to normal.
False Paths and Red Herrings
While troubeshooting this problem I went down many false paths including:
- suspecting the recent Windows 7 updates
- suspecting a virus
- suspecting a rootkit
- suspecting some start up process