comp BSOD's on boot only after its been left off for hours...details w

This is the most obscure thing I ever encountered on a computer. The first time I turned on my computer it froze up at "Loading ASUS express gate" this was a month ago, so after holding the power butting it reboots and I install win 7 and everything works great.

I do a few reboots and everything is good but then I turn my comp off for a few hours and come back and the comp says I have corrupt files such as.....

(I have had this come up over the past month so im just going to list the ones i have written down)

0x0000001e

0xc00002221
windows/system32/boot/winload.exe

0xc0000221
hal.dll is curropt or missing

0xc0000001
windows/system32/config/system

STOP c000221 unknoow hard error
systembroot/system32/ntdll.dll

now what I do at this point is usually reboot the comp a few times, play with turning ASUS express gate on and off, then I boot up and eventually I get in to windows and everything works great when i'm there I can reboot and do everything but if i leave my comp off for a few hours i get the errors and have to play with rebooting the computer to get back into windows .

I have also see bsod's for NTFS errors IRQL_NOT_LESS_OR_EQUAL (something like that) and ones that say MEMORY_MANAGEMENT

Now the weird thing is that just rebooting my comp with the power button has always fixed it (and enabling and disabling express gate) and I get into windows and it all works fine. But I cant get the windows repair to do anything ive trying all the bootrec/ rebuild bcb and all the tricks to fix it. I have reinstalled windows did not clean format however. I have changed SATA cables changed sata ports tried booing with out the HD tried booing with out the CD drive but I will always get the errors.

My computer is
Phenom II x4 955 BE 3.2ghz
4gb 2x2gb of corsair xms3 1600mhz with the 9 timing
WD caviar black 1tb sata 6/gbs
Asus m4a87td evo motherboard
EVGA gtx260 core 216 sc
win 7 home premium 64bit oem
hardware is all 25 days old

and my question to everyone is...WHAT IS WRONG WITH MY COMPUTER?

I'm about to mail the parts back for RMA in a few hours if I cant find whats wrong so any thing is helpful I have tried everything I know and googled for hours.

and just to be clear my comp never has any issues running. The bsods are always just as the windows 7 logo finishes forming and it would go to my login screen and the missing files are before that.

Even with express gate disabled my computer will have the boot issues with corrupt files or a bsod after the windows logo forms

I dont think it a ram issue because my ram is working, and the errors dont seem to be real seeing as I get into windows fine after a few forced reboots :/

Thanks for the help but I cant get memtest to work I have tried to burn the ISO on 3 cds in different ways and I cant get any of them to be recognized as a boot able cd :/ Does anyone here have the file I can just download and burn rather then play around with it myself because clearly I am doing something wrong

Ok thanks a lot and the if the BSODs are from RAM what do you think the windows missing and corrupt files are the result of?