Computer freezes

I am having problems with my computer freezing. Its an HP 8230 laptop. I had windows installed before with no freezes at all, I reloaded windows and now at random times, it will freeze. If I go into device manager, sometimes, not all the time, there will be a n exclamation mark beside the wireless card, and my card reader. IF i go into properties, it says that this device failed to start, error code 10. I have tried new drivers for both devices.