look, nobody here cares that you have a 7800, and compared to a 7800, the 6600GT does suck. but then again, the retail price for a 6600GT is under $150 while the 7800GTX is around $600. do you understand the concept of midrange hardware?
and if your brother has to run BF2 on low on a 6600GT, than he is having major hardware or software problems.