I recently replaced the motherboard in my aunts laptop because one of the IT guys she knows from work determined it was defective. Even though I had my doubts about that diagnosis, I ordered a replacement board identical to the defective one.
At this point, the laptop is extremely slow from POST to BIOS it takes 5-10 minutes. When I just let the computer go on its own booting up, it never gets past the HP screen. it only loads that and then automatically reboots itself. That is the only thing it does by itself.
In rare cases, the system is able to start normally, but usually it will just continuously reboot, suggest startup repair or crash completely.
I've tried using a Windows Vista Recovery disc and performing system repair and memory diagnosis. For now, I didn't try the system restore.