Hi xXSkyK1llerXx,
Welcome to the HP forum!
Thank you for you post, I will do my best to assist you.
I understand you tried to upgrade to Windows 8.1 , but before it completed, the unit overheated and shut down. When you restarted the unit, you received a message, it was restoring the previous version of Windows and died. Now when you startup, it goes to the bios screen. I suggest you restore the bios Restoring the BIOS to start, then do a system recovery.Performing an HP System Recovery (Windows 8).This should bring the unit back to factory. Here is document on updating Windows 8 to 8.1 to assist you with the upgrade. Updating Windows 8 to 8.1. Please let me know the outcome.