Stuttering, Small freezes and framerate Issues

[Damascus Rose]

I posted this already but I will try to go more in-depth this time.
I used to have stuttering too, still do have but very minor. I'll tell you the things I changed:

Defrag hard drive is the main one, this fixed most of the stuttering with sounds.
Updated graphics card drivers, not sure if this even helped actually.
Lowered my settings a bit and got a higher framerate, however, later on in the
game I was able to increase them without having any performance issues. I also seemed to stop having so many freezes at this point.
This is where I was able to increase them

Spoiler below!

After you get out of the mansion area and down into the part with the fuses. At least I
think this is where, could've been a bit later on.

My graphics card is Nvidia Geforce GTX 650 Ti
CPU: Intel® Core™2 Duo Cpu E8400 @ 3.00 GHz

I'm going to start a new profile and test the game with everything I can think of to make this easier for you Jens.

In the start, there are still stutters and messed up framerate even with all graphics settings turned to low, vsync is off, and the program is set to run with realtime priority.
I also noticed stutters when I was editing settings in the menu.
Actually, these settings didn't seem to have any effect on performance
at all, I would get the same result with maxed settings and with lowest.

I tested this again with the resolution at 1600x900 instead of my native 1920x1080, there was no difference.

I then disabled every background program I had running, steam windows, antivirus, Skype, even this browser I was writing this post on. I noticed visible improvement (resolution at 1600x900, lowest settings), although there was still some small freezes and frame drops. Turned all settings to max, no different. I then restarted the game in my native resolution, loaded it up and I experienced more freezes than I had with those settings on 1600x900. All of this while I had the program in realtime.

Tested TDD again, had no stuttering whatsoever. This is a very unique problem indeed, my friend plays AMFP with similar specs to mine and he doesn't have any problems at all.