The best program is fraps as far I know.
But I recommend to put your resolution lower.
As DRk said, I am not sure your able to record.
I am using DDR2 4 gb RAM and a vid ati randeon 5770, 1080p resolution, E8400 cpu 3 ghz.
- ENB mod for loading more objects.
- High quality settings mta.
Will be as result 20/30 fps.
Recording program's are heavy, I can tell you that. But you can always try fraps.