Hi again Jade!
Can you boot into Safe Mode? If you can get into Safe Mode, you need to disable Automatic Restart so you can see what is happening. To change the recovery settings and disable Automatic restart:
1. Right-click My Computer and go to Properties > Advanced
2. Under Startup and Recovery, click Settings to open the Startup and Recovery settings menu
3. Under System Failure, uncheck the Automatically restart check box, then click OK as needed to exit out
4. Restart the computer and see what happens
At this point, when/if a fatal error occurs, it should not automatically reboot, but give you the BSOD (blue screen of death). This does not fix the problem causing the fatal errors, but it does stop the endless reboot cycle and hopefully allow further troubleshooting.
You mentioned the mouse, do you get a BSOD without the mouse?