You can always put that hard drive in another computer in order to access your data.
From your description this is not a hard drive problem.
Until you actually start to load Windows (or any OS) your hard drive is not in the starting equation.
I'd suggest running MemTest but you need to at least be able to get to the boot phase.
MemTest
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Try running
MemTest.
If the computer will not POST and get to a boot level try clearing your CMOS.
How you do this depends on your motherboard.
What is the make and model of the motherboard and or computer?