I just wanted to add another post to explain how I got here and what worked for me. 
I arrived here because I lost my ability to detect my iPod after updating to Service 
Pack 2 on my work computer. I ran the SP2 update and then iTunes would not detect 
my iPod. Apple's website suggested that I look to a Microsoft KB article for a fix. 
The Microsoft KB article suggested that I contact Microsoft support for a Quick Fix. 
I have NEVER contacted Microsoft Support, and I don't intend to start now. I wasn't 
able to locate the Quick Fix file online, but I did find these forums. I tried the 
apropos fix in Safe Mode, but that did not restore my iPod or my missing Device Manager 
items. The corrupt registry key fix listed here did the job. In my case there were 
literally hundreds of entries containing "$%^&*()01234" or repetitions thereof. The 
solution is to 1) access your registry via Run>regedt32.exe
2) Search for keys containing "$%^&*()01234" or longer repeating strings of the same 
characters.
3) Make sure you have Full Control permissions on the root that contains those keys. 
Highlight, right-click, Permissions.
4) Delete all of those keys. It takes a long time. Keep searching and destroying 
until there aren't any more remaining. 
5) Reboot
6) Jump for joy that your iPod is back.
7) Scratch your head as to why Apple couldn't have provided a more direct link, or 
why MS created such a heinous bug in the first place...or why they couldn't have 
at least told us in plain english how to clean up their mess.