Storage space issues: HP Spectre x360

[Josh-B]

I have had a fair few issues with this computer over the last year and a half. I will quickly try to summarise everything that happened below.

1) Bought the laptop in mid-late 2019. I successfully used it for nearly 3 years for my university projects, programming and gaming. Had very few if any issues with it.

2) Blue screened last March (2022) and had to reboot using an installation of Windows from an external drive. This meant that I lost all the files that were stored on the PC, but that was fine.

3) Noticed that the bottom cover had started to come loose. Fortunately, the warranty on the laptop was still valid so I had it repaired. They replaced the battery (which was apparently what caused the issue with the panel coming loose) and the fans. Upon return, everything seemed to be fine.

That brings us up to now. I am having problems with storage characterised by 2 issues. The first is that my C: drive only shows 90 GB of space but I know that the PC should actually have around 952 GB available (indeed, this is the case when I open my storage in the settings). I'm not sure where this 850 GB discrepancy is coming from and would like to know. Secondly, the PC is almost full despite me not being able to see where all this storage space is being taken up. I have tried all the normal procedures: clearing the temp files, using the free 30 day trial of TreeSize to analyse all my files (which managed to clear about 5 GB by allowing me to delete the `found.000` folder), running `chkdsk c:/` and `sfc /scannow` etc. I am now at a point where I have nothing left to try and every time I look this issue up online, I get another laundry list of all this things I have already tried. I am also certain that this is not a malware issue because, after reinstalling Windows from the external drive, I only downloaded a few applications which I had already downloaded in the past. Considering that this issue did not exist 3 years before the bluescreen, I am pretty certain that I haven't downloaded anything malicious (I am also pretty computer savvy and don't download things unless absolutely necessary and after quite a lot of checking).

Any help with this issue would be greatly appreciated as not having the TB of storage I originally paid for is very frustrating. I have also included a screenshot below of my storage settings which shows that the vast majority of the space being used is not accounted for. Thanks!