1% of the problems faced by Windows 7 users occur during installation, according to a study made by the iYogi customer care company.
Most complaints came from users who got installation problems. Others complained that the are missing components and and applets after the installation, while some users have noticed the absence of the Aero theme.

Here's a list of 10 most common problems encountered in Windows 7:

1. Installation Problems: 31%
2. Missing applets and components: 26%
3. Problems with Aero theme: 14%
4. DVD drive not available in Windows 7 (though it is visible in the BIOS and driver works fine): 8%
5. Hidden file extensions: 6%
6. Too many minidumps: 6%
7. Aero Snap problems (option in Windows 7 that allows moving and repositioning windows): 3%
8. iPhone doesn't sync with Windows 7 (usually with 64-bit edition): 2%
9. Personalized Icons are changed when applying a new theme: 2%
10. Taskbar problems (the inability to distinguish an application that runs from a taskbar icon): 1%