im actually writing this for a friend but hes having issues atm.

the problems he is having is stuttering in windows 7, he is using DPC latency checker to check the lagging and he gets massive red spikes.

you can hear crackling through the speakers everytime you get a red spike, the pc will freeze sometimes for a couple seconds.

after a while the red spikes become less frequent but still kicks him out of LFS for apparently laggin when he is driving round and makes the sound go all crackly

his system specs are

win 7 64bit
Q6600 (default)
not sure on m/b
4gb ram
net gear network card
nvidia graphics (fairly decent)
650w power pack
2 monitors

all drivers are up to date and its a fresh install of win7

we have tried;

disabling audio enhancements
disabling wmpnetwk service
removing 2nd HDD
running a wired connection to the pc rather than wireless


he didnt have this problem on vista but as soon as he swapped over to windows 7 it all started to happen.

Is this issue only in LFS, or other games? What about playing mp3 or video files?

I'm having kinda similar problem, everytime someone leave pits, my picture and sound frezze for about 0,5-1 s

I had a similar problem that was caused by the onboard Network card of my MSI motherboard. It seems the Windows 7 drivers for that card were not so good. It did work ok on Windows XP
I bought a D-Link 10/100 network card and switched off the onboard card and used the D-Link instead and I've not had any problems since.

Also if you have an MSI motherboard make sure you uninstall the smart doctor utility that may have been installed from the drivers disk. That caused me another stuttering problem that occured when you touched a barrier or another car, the game would freeze for 1 - 2 secs after the impact.