Prototype audio fix windows 7

Hello,
i installed prototype in my pc, it is working but there is an audio problem.In the cutscenes the audio is choppy. this is irritating me lot. i downloaded a editor names sc****** editor(i forgot it's name) and extracted "00audio.rcf" in audio folder. i followed all steps to fix it's audio problems from other sites. but now also there is same problem.
My PC Specs are:-
Processor:-Intel Dual Core E2140 @1.60GHz
RAM:-3 GB
HDD:-1.5 TB
Graphic Card:-2 Nvidia 9600 GT (1GB each)(In 2-way SLI)
Please reply me quickly as possible to how to fix it's audio problem.Thanx in advance