Windows 7 64bit extreme compatibility errors

Ok, so i'm going to attempt to describe in detail what exactly is happening here.
My computer has 2 hard drives. One is a 320gb SATA and the other, a 180gb PATA.
I've had windows XP professional SP3 installed on the 180gb HDD for a very long time with absolutely no problems. The main use of the 320gb HDD was storage.
A couple of months ago i decided to give Win7 a whirl so i downloaded the 7100 RC 64bit build. I backed up the data on the 320gb HDD, i formatted and i installed win7. After some time, for absolutely no reason, my steam client running on winXP stopped running. Every time i try to start it i get a "Fatal Error: Failed to load platform modules".
"Why is this relevant?" you might ask. Well, the same time steam stopped working, WIN7 started giving me EXTREME compatibility errors...
What do i mean by extreme? Well, absolutely nothing works. I can't start notepad, i can't start MSpaint, i can't start any EXE whatsoever because every time i get an error telling me that the program ws not designed for the current operating system i'm using. I can't remember the error by heart but i know it's a compatibility issue. The OS boots fine, i just can't use anything on it.
This has happened 3 times now. Every time the same thing. I format both HDD's, i install win xp and everything i need on it, then i install win7 64 bit and install everything i need there aswell and then after 2 or 3 weeks of absolutely smooth and trouble free OS goodness, everything goes to hell. I have no idea what's happening or why. I really need help since i can't live through another 2 formats/installs/backup moves and such.
Feel free to demand any further info and i will be more than happy to provide it.

here's some basic info on my PC specs:
CPU: intel core 2 duo E6750 @ 2,66Ghz (OC'd to 2,85Ghz)
GPU: nVidia 9500 GT
MoBo: ConRoe 1333-D667 Rev. 01 (this one)

RAM: 4gb (2x 2GB Kingston KVR667D2N5/2G) 2gb PC2 5300 CL5 240-pin DIMM
Hard Drives: 1x Western Digital (WDC WD1600JB-00GVC0) PATA
1x Hitachi (HDT725032VLA360) ATA
i recently bought the 4GB of ram only to find out that my mobo only handles 3,2 GB of that, the rest being used for something i still dont know (no not extra GPU memory)

For the Steam error, I found this: https://support.steampowered.com/kb_...8142-EYLV-8657

I honestly don't know what the Windows 7 issue might be, but I can hazard a few guesses. Either some hardware component isn't stable, or more likely some software issue is occuring. Does the OS have anti-virus and other protection installed? Can you provide a screenshot of the error message? Does the issue occur with the system at stock settings? Is the onboard GPU auto-disabled in the BIOS?

What BIOS version are you on, and did you install all the most recent drivers after installing Windows 7? Download links are at http://www.asrock.com/mb/download.as...7%20R1.0&s=775

Regarding RAM, 32bit operating systems can't use a full 4GB of RAM. 32bit versions of Windows 7 are limited to 3.15GB of RAM as a best case scenario.

here's some further details taken straight from my bios (just in case they might offer further insight into my hardware specs)



and here's the Win7 error:
the screenshots are from trying to start MSpaint and internet explorer but i get the same error for EVERYTHING:


as for the steam error, i have tried EVERYTHING...
those steps on the steampowered forums where the 1st i followed but all to no avail
My win7 didn't have anything but the win firewall as protection but i know how to take care of my pc so i don't really need an antivirus since i've never had any viruses/trojans/keyloggers/worms or anything of the kind
EDIT:
i have an American Megatrends BIOS version P1.80

In the last BIOS screenshot, I see two things that are wrong:
1) Set the CPU frequency to 333MHz.
2) Set the PCIE frequency to 100MHz.

PCIE at 120MHz is pretty outrageous. That's a 20% overclock on a bus that was never meant to be overclocked, and interfaces with a whole raft of parts including add-in cards and some SATA controllers.

This issue sounds like a memory or hard disk error.

i tried setting the values you suggested but my PC wouldn't pass the POST at 333/100 so i set it back to it's default values (333/115)
still no success...Win7 still gives the same errors

Okay, I noticed the same thing as Thrax here... your PCIe Frequency should be 100. Anything higher will risk problems... and a PCIe frequency of 120 is almost a guarantee to cause hard drive corruption and other serious problems. I frankly have no idea how your board even works at 120MHz, many don't even POST beyond 110MHz. That must be a very forgiving hard drive and graphics card... For example many serious overclocking motherboards don't work with most SATA hard drives beyond 105 PCIe, mine included. So I'm 90% sure this is the cause of all of your problems right there.

First, disable your overclock and reset the BIOS to optimized defaults. Save, reboot, and re-enter the BIOS to see what it says your PCIe frequency is. If it is not set to 100MHz then set it yourself... at this point you should reinstall your OS.

If your system is really operating at 120MHz PCIe bus then whatever corruption has occured to your OS has already been done and can't be reversed, you're going to need to state with a clean slate. Sorry, but there's no way to fix it.

I strongly advise to avoid overclocking at all on that board as well.. most boards allow users to lock the PCIe frequency to prevent this from occuring, but yours apparently does not. A small 200MHz CPU overclock shouldn't tangibly affect the machine anyway.

As a side note, with your 9500GT installed your Primary Graphics adapter should be set to PCIe, not PCI. What settings are available under "Overclock mode", as well?

first of all thanks alot for that! I think that's the first coherent solution i've gotten in a VERY VERY long time. Second of all, my def PCIe frequency is 115, if i i set it to 100 my pc doesn't pass the POST (it doesn't boot it just closes down and reboots with the default settings).
As for needing to re-format everything and start from scratch, i really dont mind it as long as it fixes my problem.
As for passing the POST 360/120 was the max i could do whilst still having everything work fine. If i did it any higher, one of my HDD's wasn't recognized anymore
EDIT:
under "Overclock Mode" there's Auto, CPU/PCIe Sync and CPU/PCIe async
i was using the async to get my CPU to 2,85Ghz

Hi!,
Have had same issues with Win7 works for a few weeks ok then will not alow me to install programs same as you..I use ACRONIS to make backup files starting as soon as I install a new OS then after several programs and then again and again...you can then go back without having a major install..found that all the problem program installed early on in the peace with no troubles and were only a problem if you tried to install them several weeks later..have been wondering if some of the later Win7 updates by microsoft were perhaps part of thr problem?? ..Try installing your programs with the updates turned off..and backup before turning updates on!!..Your Hardware problems..can't offer any more advise than you have already received but it does seem strange it works ok with XP ..LUCK

Devil, it sounds as if 115 on your board is really 100... the first sign that the PCIe frequency has gone beyond the hard drive's capability to operate is when the SATA drives are no longer detected during boot up. This only confirms that you were right on the edge, and close enough to be causing data corruption. If it defaults to 115 then just leave it at 115... is this the same setting "failsafe defaults" sets it to just out of curiousity?

Async should have locked your PCIe freq if it was possible, "Sync" would likely make it worse. I'd leave this at board defaults and again just don't overclock.

Ronpack, the PATA drive had XP on it, and PATA controllers mostly use the PCI bus, not the PCIe bus. Most extreme overclockers use PATA drives for this reason when they modify the PCIe bus frequency.

again, THANK YOU for the info, this is priceless data that i haven't gotten anywhere else.
As for failsafe settings, my board doesn't have that option (lol) it only has the optimal defaults.
I'll be using default settings from now on and i'm gonna start the process of formatting/reinstalling in a couple of hours.
Would anyone suggest against doing a quick format? Should i do the long and boring one?