Win2k hangs during startup

The first time this happened Win2k stalled at the OP prompt list where you have options to choose which operating system to activate. The computer did this for two days until it mysteriously fixed itself. It ran as normal for three weeks til now when it hangs at the Win2k loading page. I’m now in my second day of being shut out of my computer.

Can you advise me on how to fix this?
Thanks