Thanks for the update.
As you had already saved your data, a clean install of the OS would have been the better option.
Your MB will not run well with a 4GB and a 2GB configuration. You were going to install 8GB, 2 x 4GB = 8GB. You will need to start with the one stick of 4GB in slot #1, (closest to the CPU) Add another 4GB of matching RAM at a later date.
IMPORTANT. Ensure you only have the OS HDD and the Optical drive connected.
Follow the tutorial to do a clean install of windows 7
Next, Run the disk that came with the MB to install drivers.
> run the disk that came with GPU.
> Update the OS.
Install Anti Virus, I use Avist! Free, > http://www.avast.com...CFUxA6wodR3oAvg
Please do not install any other programs at this time.
How is the system running now?