Win XP64 Issues

Two issues at hand
First I decided to migrate from winxp pro to winxp 64. Since then I have had two blue screens and multiple lockups while playing battlefield2.
I have installed all the 64 drivers I needed and I updated bios to the latest version. Now wondering if I have made a mistake, I was going to buy
another two gigs of ram in order to squeeze more performance out of older hardware.
The other issue
After installing all progs and a game, I decided to create another guest profile. I was stupid and was not reading thoroughly while clicking next and so on.
What ended up happening was I created a new admin profile. None of the progs ported over so I had to copy paste all shortcuts, etc. That said, is there anyway of removing newly created admin profile and just using the default admin profile, other then in safe mode? I have tried deleting all files relating to new admin profile and deleting all strings in registry that displayed new admin profile's name. After rebooting, the new admin profile still comes up, so there is a back-up profile and I'm not able to find it.
heres my hardware specs if this helps with first issue:
Amd64 3500
Asus A8N-SLI Deluxe
2gigs Corsair ddr400
Gf 7800GTX
Sony DvD burner
500watt pwr supply

Thank-you in advance