I don't know much about computer hardware. But, it might be the board components. Or, it might be the hard drive itself, or the hard drive program.
It helps not to be shy about electronics. When looking at the board, the easy steps are CMOS battery replacement, memory stick replacement, or shorting the CMOS memory prongs, or replacing the entire motherboard and its components.
1. To save the hard drive contents, try shorting the CMOS prongs. Just locate a set of three prongs and their connector. Shift the connector from one position to the adjacent position, and back to the original position.
Then, try booting up. It may give you a choice of commands. Probably just F1 will open Windows.
Sometimes that works- temporarily. Things may eventually fail once and for all- so if it solves your problem, work to recover and back up the images, or whatever.
2. Replacing the CMOS battery may help.
(Link)3. You may have a boot virus. That may require running your system disk for complete data wipe and reprogramming.
4. The board may be getting ready to crash. That might be the problem. In that case, the hard drive may still be uncorrupted, and reused with a new PC motherboard, etc.
5. Might be a memory stick. It's a little difficult to find replacement for some older memory, sometimes. This is not as likely as the motherboard, itself, having a circuit failure. IMO.
Just a few thoughts. I just bought a new D-Link ADSL modem which was quickly spammed by some malware. I would have to update the firmware, I think. However, I'll just trash it and get one that is preconfigured. The hacker turned my admin page- pink, with neat little pop-ups. My old modem is not vulnerable to that stuff.