The extreme variety of ‘fixes’ that can be found for STOP: x000000F4 on the internet show that this is a very generic error code that can be caused by almost anything. It essentially says that some system function exited abnormally and unexpectedly.
 
It could happen if some hardware component is starting to fail, which could cause the OS code to get interrupted at any time when doing any function. Because of that, it might have different register settings each time.) Or it could be a hardware driver that’s not completely compatible, or almost anything.
 
The only way to be sure is to begin testing every component in the system — hard drives, memory, motherboard, connectors, you name it — plus all drivers (generically, then one by one) until some flaw is found.
 
If you already know how to do that, you can get started. If you don’t, then the system needs to be checked by a professional. An alternative is to get a new system. The current hard drive can probably be installed as a second drive in a new system, but it might be the failing component.
 
Tom