Windows 7 Winodw 7 Pro 64-bit wierd errors at installing

Hey all this is my first time here so sorry if I sound n00bish ^^;;

Okay so i finally got a ram upgrade in my Acer Aspire M1100 Desktop and went to install windows 7 Professional 64-bit

I installed it fine, however when after my computer restarted to get to the "windows is setting up computer for first use" screen, it instead booted to a white screen.

I thought this was odd so I tried to restart window 7 in repair mode, computer rebooted. Then i set it to run in last good configuration and all seemed well, the "windows is setting up computer for first use" screen finally came up, but then my computer restareted itself, i tried again, same thing, it can't get past this screen and i don't know why. If anyone knows what i should do i would appreciate it. here's my computer's specs:

Acer Aspire M1100 Desktop PC
Primary OS: Windows 7 Professional 64-bit (was Windows Bista Home Premium 32-bit)
Secondary OS: Windows XP Media Center Edition 32-bit
RAM: 6GB (upgraded from 2GB)
AMD Dual Core Processor
250 gb hard drive
ATI Radeon X1250 Graphics Card
Realtek HD Audio Jacks and drivers
Logitec USB Audio Drivers