x64 - Drive Letter Change - BSOD

Hello! I've searched in here, and found some good threads on the following, but none that ended badly, as mine has! Any help?

Dual Boot Win7 x64 beta
XP x32

After installing Win7 into a new partition, the OS started up fine from the new dual boot screen, but I didn't have access to my Win XP partition from within explorer. In disk management, I was able to add a letter to my WinXP volume (I took the next available "O") and it popped up in explorer no problem. However, after restarting, Win 7 begins to load, then BSODs way too fast to think about catching with camera. I got the option to run startup repair at the restart, and I did so. The conclusion there was that I had plugged in a device during the last session that was now causing problems. That is bogus, unless that device is my newly lettered partition. I read many a thread in here about re-lettering a partition that had lost its letter in the intall (usually the other OS volume in a dual-boot environment), but didn't see those posters then have issues upon restart.

I can boot into XP, although here now NONE of my drives have letters.

Any Help? I really was diggin' my win7 time, and really enjoyed taking advantage of all my RAM and x64 versions of CS4 and CAD.

Thanks.

-JN

Is it possible to try another repair and chose a system restore to see if that gets you back in. You should get the repair option if you press F8 om the boot selection screen.

When going through the startup repair, I did get the recovery option. At the time, I chose not to use system restore as there was an extensive CS4 install in the interim that I didn't want to lose (I think it would have gone away, but I'm not exactly sure how system recovery points work.) I'll certainly try this if no other ideas pop up - but I would imagine that adding the drive letter again may cause the same problem. We'll see. Thanks for the quick respone!

Got it

OK - So, it had nothing to do with drive lettering, or CCleaner registry cleaning...

I tried to use a restore point, as suggested, but I hadn't created any, apparently, so no go there. Then I went in under safe mode, ruling out the essential drivers, then started opening programs. Turns out uninstalling AVG 8.0 did the trick. Huh - one of the three antivirus solutions that MS recommends for 7, doesn't really work in seven.

So, I'm going to try either Avast or Kapersky...I'm awaiting a final read through of the relevant section here.

*Sigh of Relief*

-J