My windows pc is not booting,cannot reinstall windows - is this because of mobo or HDD

[paglabhola99]

I need help .Since Ten days back one of my windows pc (os 8.1 x64) won't boot. The computer shut down(BSOD occured) suddenly when I was browsing . After that I showed " Reboot And Select Proper Boot Device " . I saw the bios settings whether HDD is set to be the primary boot device but I didn't found it .Also in the bios I saw no hard drive detected .Two days later I cleaned dust inside the CPU , took out my 2 ram sticks and inserted them.After that I started the PC and it worked fine . Some of the files were not backed up.So I started backing up. But I was very busy that day and I shut down my pc and left my room .They next day I switched on the Pc and started acking up . But again BSOD occured . I was unable to see BSOD messages as auto restart was enabled by default.After that I have not been able to start the PC .Every time with normal boot or safe mode BSOD will occur. Still some of my docs and downloads were not backed up. I have decent sort of knowledge in software but I am very bad dealing with hardware faults.I called one of my friends who have repaired a lot of windows pc. We didn't try any linus cd. But we tried to boot from genuine W8.1 and even W7 cd s.Every time during installation the PC froze. During initial attempts the partitions showed but after that it disn't show. We have changed both the ram sticks,tried booting with only one stick ,changed DVD/CD writer but nothing worked . What can be the problem - the mobo or the hard drive .I am very angry with myself. Some files still not backed up.I am cursing myself

I took the drive to another pc and it was not recognised.Should I change the hard drive or the mobo ( power was reaching all components).Is there any great software to recover the HDD

The day before the Pc stopped functioning I was downloading a p2p file(I don't download torrents often) .I was constantly getting "Write to disk error.Access denied". However I scanned it with EIS,mbam and zemana and everything was fine .Please suggest me what to do . Please help me to sort it out

 

[Cycloid Torus]

Sounds like bad HDD, but not certain yet.

If it were my system, I would finish cleaning the system. Then I would get another HDD and install Windows on that.

Then when it POSTs, enter BIOS and turn off 'automatic restart on error'.

I would then reconnect the bad HDD, but as a non-booting device.

Then I would try again to run chkdsk on the bad HDD ( chkdsk /r ). It may take a long time. Let it finish.

You may be able to access files when it is done. Check SMART for the dying HDD and I think you will see it is having problems.

 

[Hotlynx16]

Win 8.1 is strange, still learning about it , worked on a laptop with it and removed hard drive and was not visible on a Win 7 computer because the drive was formatted in GPT format? Had to use another Win 8 system to see it. To boot from a CD you may have to go in the BIOS and change the UEFI to legacy so it will boot from CD. The UEFI looks for specific hardware and If it doesn't see it will not boot. Probably some one here can explain it better than I. what is the PC model?