This post extends on my technical issue detailed here; it provides context, but is not necessary to understand the below.
I could find a way to remove my corrupt attribute records by running sfc /scannow (which would never find any integrity violations when complete), then chkdsk in Command Prompt, then restarting; chkdsk would delete several corrupt index records before being blocked by $I30 and needing a hard reset as before. At the first go, the 30 corrupt attributes were pared down to five, and at the second this was reduced to two. I had waited then half a month without restarting my computer, during which time it had operated completely normally. It was only when I had restarted my computer again to day that chkdsk would run again. It had deleted all remaining corrupt records, and Stage 1 of chkdsk could complete successfully, partially solving my original problem.
Unfortunately, the original error had reappeared. This time, instead of freezing at 9%, it would freeze about 33% with the same error thrice repeated:
Correcting error in index $I30 for file 109203.
After restarting, the computer had booted again (much faster than I expect from it at this age), and I immediately ran chkdsk again in Command Prompt. The results are here; though chkdsk could not continue to the end, it had stopped at the same point as when running at boot, and as can be seen, the results in command prompt are much more enlightening than there. It now specifies specific files which are incorrect, whatever that means.
The final entry, concerning privatix_js1532317223033.pac, is the most peculiar to me. Privatix is my VPN, which I have installed as an addon (version 0.19.3) to Firefox 53 for 64 bit Windows 7.
My computer is still operating normally, and besides the normal steps of backing up and thinking of how to replace my computer for when the day finally comes, how can I solve this problem specifically? I doubt this is merely an ageing hard drive if the corrupt attribute records could be cleared, no files appear to be lost and all files damaged are of the same type (and one I can recognise distinctly.)