I found a number of similar questions covering this, but didn’t find anything that was a very close match. If I missed something, I’m sorry, and I’m more than happy to check that out.
I have an HP machine which runs a kind of kiosk system on top of Window 7. Randomly, it appeared to have a “non system disk” error showing and didn’t want to do anything after rebooting. Assuming it was HDD failure, I replaced the HDD and attempted to ghost from another (very similar although slightly different) system. Using this new HDD with a clean ghost from a functional system (with the same hardware configuration), I was still presented with the same error. I connected the original drive and had no issue creating an image of it on my dev admin machine.
After doing some looking, I found that it could be the SATA cable, so I replaced that too and reinstalled the original “failed” drive, and it booted just fine. Thinking I had overcome the issue by using the new SATA cable, I left it alone only to find that the error had returned over night. I then moved to a different SATA port, and again it worked properly for at least 10 hours, only to find that overnight it had errored again.
Now I took the new HDD and restored the backup from the image I had made of the original and installed it in the the problem machine. This immediately resulted in, again, the non system disk error. I then changed the SATA cable and port, and again got the non system disk error.
At this point, I’m not really sure what is causing the problem. The drives do show up in BIOS, and when reviewing the contents (on the old and new HDDs) the boot files seem intact. It’s strange to me that they have both worked to boot at least once, but then just become non-bootable.
IDK if this is possible a mobo error or PSU maybe… I’m mostly at a loss for ideas now.
P.S.
I did just recall that they have scheduled task scripts to reboot each morning, which at least explains why it happens overnight – but I still don’t understand how a bootable device becomes “non bootable” just because the system restarts.
P.P.S
Also, I recently tried running a chkdsk on my admin machine with the old HDD connected internally, and it does randomly stop being connected (seemingly after it warms up). It randomly interrupted on stage 5 with this drive, and was never able to complete. It did list 0 bad sectors before that though, so I don’t think data integrity is the issue, more likely the drive does have an issue, but that doesn’t explain why the new HDD (with a proper clone) isn’t working consistently either.
