Mysterious intermittent freezes for not a few seconds... (Fallout 3)

Peace to your home, gentlemen.

I've been struggling with the problem for the second week and, it seems, I can't solve it on my own, so I'm asking for help...
The essence of the problem is that the game periodically freezes for a few seconds (about 10). This happens both in the gameplay itself and when loading the last saved game ...
I want to tell you right away that I tried all possible ways to solve the problem that are on the Internet (including in the foreign segment) and even more - I tried change any other settings (in game files, video card drivers, BIOS). Drivers, additional software and OS updates are the latest. The problem is observed with any builds and repacks, with and without mods...
The problem is very mysterious... because there is a machine on which it simply does not exist!

In short, there are machines:

1. Core i7-2600/ GTX570/ DDR-III 8Gb/ Win8.1x64.
The problem is relevant. But, when Win7x64 was installed on the same hardware, the problem was not observed and everything flew!

2. AMD FX-4300/ RADEON R7-250/ DDR-III 8Gb/ Win8.1x64.
The problem is relevant.

3. Core 2 Duo E7500/ GeForce 9600 GT/ DDR-II 6Gb/ Win8.1x64.
The problem is not observed ... and everything flies!

That is, it turns out that the iron has nothing to do with it, and the AXIS has nothing to do with it ... And then what does it have to do with it ?! I'm about to go crazy... can someone stop this from happening?