What is the problem for blue screen error
 

I have windows 7 64 bit and sometimes the windows crash down and blue screen come. idont know the problem may be the hard disk but am not sure please if anyone have any idea about it

85-95% ram ,change ur ram and it will be fixed.
if u have 2 ram remove one and see if the problem is still then check the other one.
if u have one ram then change it from another friend PC and check if it still have this problem .

PAGE_FAULT_IN_NONPAGED_AREA could also be caused by a defect in some driver. Does the bluescreen/error report mention a driver maybe?

Load crashdump in windbg.
the in command run
!analyze -v

to get more detailed debug information.

on board video card that use shared memory could be going bad or bad tweak. could see if the timing of this relates to any ms update that replaced 3rd party drivers. power supply voltages out of tolerance. try testing the hardware using stress test software.

Stress testing will show quickly, where the problem is. I suggest MultiCore Prime 95:
https://mega.co.nz/#!jUlF3YLT!6ol4qhE70ZAxQtX1b8qv49o88m2h2Cct3B7e3OHkAkQ
https://www.oboom.com/VI9500YO
http://rapidgator.net/file/46084abeb891986d584614ccf383f025/Prime95_multicores.zip.html

http://s2.postimg.org/yz2fyjhbd/Prime95_multicores.jpg

Just remember to start custom test, check if number of cores correspont with your task manager info, set min FFT size set 1792, max 2048 and in matter of minutes you know that your ram if faulty.

If nothing happens (no error) for 8+h, the machine is ram stable and you have a bad driver. Reinstall with different version of mainboard info drivers...

as Ahmadmansoor said is the ram problem because when i use virtual machine with 1 or 2
GB ram this blue screen come after the windows crash down however i have 6 GB ram. the question is why when i use virtual machine (Vmware Workstation 10) this problem happed
also is not happening on the first minutes maybe after half a hour or more than that.

BlueScreenView
 

http://www.nirsoft.net/utils/blue_screen_view.html

Try this to find out more information about the blue screen, and perhaps isolate a driver where the crash is happening

http://www.memtest.org/#downiso

Is a downloadable iso that you can boot from and test memory

...memtest did not stress the ram like Prime95 do... Nowhere near. But it is a good start. True. Usually I do Memtest as just boot CD test.

check your motherboard, if you see inflated capacitors, that's your problem,
if you are a skilled man, you can try to replace them

regards

If the problem is the RAM the MB should emit sound signals. But maybe is some driver corrupted.
in the most of cases, the main problem with no sound signals could be due to hard disk failures, programs in disturbance with the operating system or maybe some burnt plate in a ram, which will be tested one by one

maybe you should check your event viewer (administrative tools) and see if anything seems strange there in the logs maybe a driver problem will be there (may help to track when the problem started) .. Run chkdsk /f to check drive for simple drive error or something like that. This could be caused my many things, (bad driver,memory error, hard drive) You could also try SFC /scannow command to check all protected system files for corruption. Hope this helps a bit! :)

Once I had BSOD problem too and it was from power supply.
power supply were not able to provide stable and suitable power for motherboard.

Regards

Storm Shadow gave you the best answer imho.

If you are lazy, hiren's boot cd and use one of the tools like memtest for get a good diagnostic of your ram status.