ASUS m3n78-vm motherboard

my is problem after i installed the new mother board my pc freezes and locks up at random time, sometimes affter boot some times after 15 mins and sometimes after an hour or hour and a half. I checked the graphic card in my frends pc it and it works fine, we tested it for like 3 hours and it works fine. I can presume that the motherboard is eaven not compatible with my system or it has a manufacture failure cause with my previous motherboard that still works, only the pci-e slot doessnt this issues didn't happen my father stil uses it on his pc so it has to be the motherboard or memory. Any SUGESTION is welcome.

Windows 7 64 - bit
ASUS m3n78-vm
AMD socket AM2+ / AM2 for AMD Phenom FX / Phenom ? Athlon / Sempron processors.
AMD 64 architecture enables simultaneous 32 - bit and 64 - bit computing.
Supports AMD cool 'n' quiet Technology.
NVIDIA GeForce 8200 (MCP78S)
Dual - channel memory DDR2
Quad Core
Firstly, I would recommend running a VIRUS scan, just to make sure that there's nothing infecting your machine. Following that, I would ALSO see if a system restore (http://windows.microsoft.com/en-US/windows7/products/features/system-restore) would bring your machine back to the capacity that you're used to it working at. At the very least, you can try to rule out that it's a software issue if it keeps happening.

-- Ryan
Windows Outreach TeamFeel free to ignore the above post. It clearly has nothing to do with your problem.

Was the new mobo identical to the one it replaced? If not, you may NEED to reinstall the OS.