Found the fix, if anyone else is having this problem, read this easy solution.
I read this on a forum somewhere that multi-cores may be the cause of the problem. Essentially, the game executable is passed from core to core, causing extra overhead. This is not a problem if your CPU is fast enough, but apparently, mine isn't.
How I fixed it: I set the process affinity to 1 core, I chose the second core (Core 1, I have a dual-core), as this core has less traffic than the first. Upon playing the game, I get absolutely no lag, none. It's even better than in Windows XP. Some of you may consider that troublesome to do every time you start a game, I don't care. I have zero lag and I'm happy.
To change process affinity, just open task manager, right click on the game process, and click "Set Affinity" and set the core(s) you want the process on.
Problem solved.
Edit:
Problem partially solved. Capcom games (SF4 and DMC4 still have lag, even when running above 30 fps). I haven't tried any other games yet, but this is turning into a conundrum.
Edit Edit:
Turning off threaded optimization in the NVIDIA Control Panel under "Manage 3D Settings" helped so much. So far, no lag above 29 fps. No lag whatsoever in some games. Still have lag in DMC4 and SF4 under 30 fps, no matter what I do to my processors, so I suppose that's a graphics card issue. I do recall having lag in DMC4 in Win XP, but I don't remember to what extent. It's no biggie, DMC4 rarely goes below 30 and SF4 never (unless I increase the resolution) goes below 30. I haven't tried Halo 2 yet
![:( :(]()
. That'll be the real acid test because Halo 2 was pretty much lag-less in Win XP even at 13 fps (yes, I know my gfx card sucks, I'm getting a new one within the year).
Edit Edit Edit:
Gears of War is lagless, even at 15 fps (which it rarely gets to, but is nice because my aim doesn't suffer too much except from the jittering at lower fps). It's even better than in Win XP. Haven't tried Halo 2 yet, but I don't expect any lag at this point.
Final Edit:
Halo 2 still lags in the same way DMC4 lags D=. It is a problem in this case because Halo 2 is an fps and it makes it horrible to aim (and impossible to snipe fast moving targets) I'm out of ideas.