Hopefully somebody out there can help, as I'm no expert I'm afraid. My pc turned off during a power cut whilst I was running antivus software. When I rebooted, I got to the welcome screen and clicked my user account, it started to log on then about two seconds later logged off again. I have my xp pro cd, but the two cd rom drives are not being recognised. I've tried to the set of 6 floppy disks, but when I get to No. 6 I get an error message 0x0000007B.

Any ideas anyone?

Thanks in advance.

It looks like a problem with boot file of windows. Try it in "safe mode" or "last know good successful ..." :
press F8 during reboot process, you will see it

Try to use some edit program in dos (you can use in boot CD or rescue floppy disk) and checking boot.ini, config ... some system file; perhaps it help you very much.
At last, you can log in your system and interupt rebooting process by some solutions... It's very pity because I can't remember it clearly... sya!

Good luck!

You can get that message because:
1- Boot-Sector Viruses
2- Device Driver Issues
3- Hardware Issues
4- The boot volume is corrupted and cannot be initiated by Windows XP
Press F8 during boot process, try with "Last known good Configuration", if this does not work, try "Safe mode", if it goes in on safe mode, try to revert the last hardware or software changes made on the computer.
And, as blue eagle987´s said you can interrupt the boot process, here i leave a link to a boot CD:
Search for ultimate boot cd on www.100-downloads.com if the link does not work.

ANything can happen to your PC when the power fails.

I too would have said that you should boot the last known good configuration from the F8 options.

If that doen't work you likely have a more serious problem on your hands. You'll be lucky if all you have to do in Safe Mode is to re-install any device drivers for misbehaving hardware. But that's the next port of call.

Otherwise, and assuming you have no hardware error (RAM is the likeliest), you should file your data off to a backup device (if you can't do it on the problem PC, put the disk in an external enclosure attached to another PC and get the data off there). Then re-build your system in the offending machine.

It would be pointless doing this stuff, though, if you can't see the two CD drives.