devil may cry running in slow motion after windows update

[Callum Williams Ripley]

hi guys. i recently got a pc borrowed from a friend. he just bought it himself for a resale an i am saving for a new pc, it got devil may cry on it, it worked fine apart from a few frame drops here and there. but i have a few of my own parts ready for the new pc, radeon HD 7850 2gb gddr5, which is brand new. however it is bottlnecked because the pc is only a pentium dual core @ 2.6 ghz. the problem is, it runs in literal slow motion. not low fps, slow motion. its really annoying because its a fast paced game. i dont see how it could be doing this. in the credits screen before the game, the capcom logo and amd gaming evolved titles appear, the video seems to be fine but the audio cuts out for a moment then its fine. this is probably something to do with it. the audio is fine, but i guess this is just slow also.

full pc specs:
intel pentium dual core @ 2.6 ghz
2 gb ddr2
windows 7 home premium 32 bit
radeon hd 7850
80 gb hdd
430 corsair psu

thanks in advance.

 

[Callum Williams Ripley]

forgot to mention the issue only occurred after windos 7 service pack 1 update.