BSODs every now and then

Need help to identify driver that cause BSODs.It all started 10 days ago.I didn't change any hardware.BSODs randomly. I looked around forum for same problem but I can't find what driver cause BSOD.
I installed all latest drivers for my GC, usb cam, chipset (ethernet onboard), keyboard and mouse.Nothing help.Looked in minidumps for driver but could not identify it.It always point to some windows sys files. I used MemTest86+ all night 7 pass/ no errors.Harddrave checked for errors/ no errors. Then I made clean install of Win 7 Ultimate and updated it.But same problem appear before update and after. Then I used verifier and it made some minidumps.
Minidumps point to sys files like ntoskrnl , fileinfo, usbport.
I opened my case and taken out TV card and WiFi (usb) and CardReader (usb) beacuse I don't use them and maybe they make trouble but it didn't help, even I get a cam (usb) off.
Only thing left that I didn't do is BIOS update for mainboard 1.0L to 1.16 (found on manufacturer site).
My antivirus is ESET Smart Security and it is up to date.
I hope you can help me.

Dumps blame nvlddmkm.sys, part of Nvidia drivers
I suspect bad RAM


Possible causes: bad RAM/PSU, incorrect RAM timings/voltages, bad Graphics card, overheating, outdated driver


Uninstall the Nvidia driver then use driver sweeper to remove leftover driver files
Guru3D - Driver Sweeper

Reinstall Nvidia drivers in safe mode
NVIDIA DRIVERS 260.99 WHQL

Test your RAM
RAM - Test with Memtest86+

I already tested memory. 7 passes no errors. I'll try install nvidia drivers in safemode.
I'll report soon.Ty for quick answer

Clean install of display drivers in safemode done.2 new minidumps.They point to ntoskrnl.exe. I already tested memory, no errors found.

BSOD usually appear why I play online game or when I surf on Chrome, Facebook games like Mafia Wars or Treasure Island ( lot of Flash ).

Thinking to upgrade my mainboard BIOS.It's still 1.0L. But comp works fine before.
Any other solution? or harder test for memory?
ty in advance.

Test the graphic card in another PC

I tested my proccesor with Prime95 and got no errors.
I tested GPU Nvidia 8800 GT with Furmark and got idle temperature 65 °C and working temp 108 °C .I read on net about 8800 GT and they said it can go up to 100 °C. This is much higher then that.
Can this be my problem? I said before that BSOD occur mostly when I play on Facebook or normal game online.
How I can fix this? Better cooler?

New minidump. Win32k.sys . Never seen before.

Anyone have solution?

I run memory test for 7 passes. Whole memory overnight.Didn't test each slot.