ATIH 2012 crashed my compueter

Yes, you're right to proceed carefully. A bad guess could leave you stuck. Key question: Did you do a full system backup with ATIH 2011 prior to installing ATIH 2012?

If so, the safest and quickest solution is probably booting to your 2011 recovery disc and restoring that backup. Otherwise, you've probably got a chore on your hands trying to discover exactly why you're getting that repetitive "blue screen" reboot with normal startup attempts. If it's giving you a chance to try F8 options, you could try Last Known Good Configuration and/or Safe Mode, but previous boot attempts may already have modified the former depending on how far they got. One likely reboot cause would be a spurious entry in the system registry hive -- e.g., one that requires the loading of an essential device driver that can't be found. But the fact that it's reaching the WinXP splash screen suggests some other type of conflict.

What type of drive is your system (C:) drive? Are they all just regular IDE hard drives?

Thanks for your reply Richard...
The C boot drive is Sata... The D (my data) drive is a pair of sata drives that are handled by a Promise Technology raid controller... and my backups are on an external 1 terabyte drive.
I thought about trying a Win XP "repair installation"... or a CHKDSK /r and fixmbr... but would that leave my TIH 2011 "mirror" backups useless since ATI places entries in the mbr? Also, what about safe mode. Haven't tried that yet... was wondering if I could get Windows to boot up in safe mode... and then uninstall 2012... would that increase the chances of being able to recover the 2011 mirror image backup? Thanks again for you advice.

I'm a little unsure what you mean by "mirror" backups, but I'll assume you're referring to ATIH *.tib file images for the entire drives (both C: and D:?) that were made in the normal way with the 2011 version prior to installing the 2012 version. If so, you basically have two different routes to choose between: either trying to fix the end result of ATIH 2012 installation, or returning to the status quo ante by restoring those pre-install backups. Personally, I'd recommend the latter choice as likely to be the safest and surest way out of the current situation, but it's up to you.

So long as you retain those pre-install full drive backups intact (along with your ATIH 2011 "rescue" disc) you're pretty much free to experiment with whatever other "fixes" you think might correct the problem. There's certainly no harm in running CHKDSK /r if you suspect problems on the system drive itself, but the symptoms you describe suggest to me that the conflicts are arising during the Windows OS startup rather than during the initial boot phase. Possibly an issue between some ATIH background autostart services and your RAID setup. The ATIH 2012 version doesn't seem to like some RAID configurations very much and has even been reported as having trashed one of them (RAID 5 as I recall) completely, although that's anecdotal, of course.