Question My hdd wont boot Windows

[Gloomi2218]

Ive had my PC for a few months now and I've had many issues with my hard drive but due to me being very busy and just being lazy, I never replaced it. Today, I was able to log onto my PC this morning but when I tried to get on this afternoon, it did not get past the windows buffering screen right after Bios. I have a few questions. Is there a way that I can check if the issue is truly my HDD? Some forums have said that similar issues have been from a faulty PSU. I've tried to use the windows safe mode thing that tried to repair it with no luck. Is there any other way to fix this issue? And if there isn't, would I be able to download windows on another drive and load it up and transfer all the files without having to pay for another copy? It seems that my current HDD still works a bit but might be missing something to launch Windows. (If that makes any sense.)

 

[Gloomi2218]

And btw by issues I mean that the hard drive can get to 100% usage by opening google chrome and at times it can be unbearably slow.

 

[popatim]

Ive had my PC for a few months now ...

Wouldn't it be under warranty?