HIDCLASS.sys BSOD and sound problems

Hi, I've been having serious problems with my pc lately, I've been getting terrible 'noise' in sound when I play virtually any game (It's noticable less often in WoW though compared with other stuff, and music and movies are fine from what I've seen, just games) and there have been noticable performance drops too. I'm not sure when this started as I've been doing exams for the last couple of months so I've not been using my PC as heavily as normal, but it's been going for a couple of weeks now and it's really frustrating so I tried to do something about it today.

I thought it was probably a driver problem so to get to the bottom of it I ran the built in verifier and selected only my Nvidia and X-Fi drivers, it gave no errors so I did it again this time with all drivers selected and got a BSOD about 'dadder.sys' which is my mouse, I updated the driver (although when I tried to update the firmware on the mouse it failed, which might be significant? I tried a few times) and restarted the PC, this time I got a BSOD on 'HIDCLASS.sys', MSDN tells me that it: "provides the system-supplied HID (Human Interface Device) class driver" and im not entirely sure what to do about it, I'd appreciate any help! (I've run the seven forums diagnostic tool and attached the results.)

My Specs are:
Q6600 (Not overclocked)
8800GT 2GB Ram
Creative X-Fi Fatality Platinum (Not sure of the exact name, something like that ) I've updated my graphics, sound, mouse and keyboard drivers. Oh, and I'm on Windows 7 64bit.

Bad news. These dump files reveal several serious driver problems including HIDCLASS.sys which is a system driver. The OS needs to be reinstalled. You can try a repair install first, but that may or may not fix the problem. Also, make sure all your data is backed up.

http://www.sevenforums.com/tutorials/3413-repair-install.html

Ah. Well at least it's not a hardware problem and I was thinking about reinstalling anyway, thanks for having a look!