First of all, escuse me for my bad english.
Well, I have a fixed PC that I have bought 6-7 years ago. Recently, i have bought a new graphic card AMD radeon R7 250 and installed it.
At the begining, windows 8 detected it as a "basical card Microsoft" or "Carte de base Microsoft" in my language. After an installation of the drivers, windows detected the card right. But the preoblem is not here. After 2-3 hours of games, my computer just crash and reboot without any message. i tried to reinstall the drivers, with another version, or a complete reinstallation of windows, and the problem is not resolved.
I don't know what to do.
My PC config :
NVIDIA nForce 980a/780a SLI
AMD Radeon R7 250
Realtek PCIe GBE Family Controller
MSI MS-7375 1.0
AMD Phenom X4 9850 Black Edition Cadenced to 2.50 GHz
4 Go total memory DDR2 to 399.98 MHz
Hard disk SAMSUNGHD502IJ of 465.76 Go SATA II
HL-DT-ST DVD-RAM GSA-H55N
NVIDIA Corporation MCP72XE/MCP72P/MCP78U/MCP78S High Definition Audio