No specific ideas. 1. Update drivers (especially if you used the CD the mobo came with to install them) - at least chipset, and video-card (including IGPU) 2. Update BIOS/UEFI if it's using an old one < 2.30 3. Does "Dr. Debug" the error display show any codes just prior/at the error/reboot (other than A2, AA, AD, AE, AF, 04)... might have to take the side panel off if not visible. 4. Windows Vista/7/8, Linux? BIOS Stuff 5. Try disabling C3/C6/C States... Advanced/CPU Configuration 6. Try disabling Render Stand-By... Advanced/Northbridge Configuration 7. Try disabling Deep Sleep... Advanced/Southbridge Configuration 8. Try disabling Rapid Start... Advanced/Intel Rapid Start Tech. 9. Try this 10. Give up and don't use sleep. Z77 Ext4 Downloads In no particular order.