I've been looking for some months about this problem and still can't find anything, so I ask the community.
Some months ago, I buyed a new computer :
- intel Q9550 quad
- DP45sg motherboard (which use IDT HD audio drivers)
- 4 gig corsair ram
- ATI HD4890
audio and video drivers are updated to lastest version.
I had no problem with XP, but when I installed Windows 7 (64bits), I started to get a wierd bug.
At random times, the computer seems to freeze for about a second then get back to normal. Everything freezes, mouse, graphic and if there's sound playing, it seems like it's repeating the same sound at incredible speed until the lag ends. Here's a mp3 to show you what kind of sound the lag makes :
This is a common symptom for when a Hard-drive is broken, mostly due to a physical crash. If it's not that, it could be any number of things.. both hardware and software wise. You may want to have your rig checked by a professional.