Lordluud2 you indicate you are noob at computers and since none of your games, nor even FS9 will work, I'm wondering if you have the latest BIOS, drivers, etc., for your system? If not you might want to reconsider re-installing windows with everything updated. I did a lot of research before buying my parts, and if IIRC the Pt6 board had issues with the bios that shipped with it, and/or the ASUS driver-install disk. Many people did not get the performance they expected until updating everything -- manually.
It's very easy to update the BIOS with a flash drive, and you can download all the latest drivers for your board from the asus site. Alternatively you could just update the bios without reinstalling windows and see if that improves your performance. Otherwise I would start from scratch.
I have built many, many rigs in the interminable quest for the ultimate FSX rig, and can tell you if you do not install the latest bios and drivers in a particular order flight simulator performance can suffer.
Also, placing everything on one large 1.5 drive is just not the ideal setup. Once you start loading that disc with data and everything else that gets placed on it by virtue of using the computer your performance is probably going to suffer even worse. Even with very little on it, it is still, physically, a big disc. Better is OS/FSX/programs on one drive, and data on the other (use the 1.5T). Ideal is FSX on its very own drive. Do you have an extra disc somewhere? Can you get an extra (smaller) drive(s)?
My system is:
Asus p6t deluxe v2
i-7 920 @ 3600
2 300 Gb Velociraptors (1 for OS/programs and one for FSX)
1 500 GB WD "green drive"
BFG 285 GTX OC
12 GB Corsair 1600
FSX is still not 100% smooth at the moment, but I have not done any fsx.cfg tweaks. I have installed everything per NickN advise, and also nHancer exactly as detailed. That and installing FSX on its own drive helped quite a bit.
My performance is similar (not quite but almost) to these vids:
http://www.youtube.com/watch?v=5PGmbF4YlKMhttp://www.youtube.com/watch?v=DkbPalZgKPsIf you watch those carefully you will see even they are not 100% stutter free, and they are using payware textures, while I'm still using default fsx ones.
I have my rig oc'd with HT/sidestep technology disabled, and BLCK set to 180. Everything else is AUTO that is a pretty simple OC. You can also use 170 or 167. I have a nice, and relatively inexpensive GeminII S cooler (it has a nice copper base and pipes) with two 92mm fans on it. My i7 tops out at 55C in a very well ventilated case.
The other issue, as mentioned, is your vid card. Again I did a lot of research and reading articles about 295 it seems that model (or at least some of them) has "power saving" built into it. This is all nice and well if you are a regular user, but probably not so great for FSX use. Can you exchange that card? Wouldn't it be nice if you could and everything worked? U want a vid card with one core and 1GB memory. That's something that needs looking into as well.
Hope this helps. I would start with updating BIOs, see if that helps. If not, I'd start looking for another drive or two. They do not have to be raptor drives. If you do this it will necessarily require re-installing windows/drivers, but this is not a bad thing. Do you have a friend/relative that is more adept at computers that could help you? After you get that setup then start oc if you wish.