Can't load 'User'

I'm having trouble accessing any User after the Welcome screen.

Windows XP SP2 boots okay to the user Welcome screen. When I pick a

user it starts 'loading the settings', thee background comes up, no desktop

icons and then suddenly it goes to 'saving the settings' and back to Welcome

screen. I first tried rebooting and also Safe Mode (using Administrator) but

same result.

Figuring XP needs a driver or repair, when I try to use the OEM XP cd to

boot it gives me "install XP, create or remove partition" When I touch any

key it goes to blue screen. 2 messages - either 0X8E or 0X50. From there

I've tried removing recent slave HDD and added SIMM but no change.

BIOS settings look unchanged.

Any suggestions?

Thanks

Rob