really slow computer

the lack of HD space would definitely be impacting Windows performance.
as to whether that is the only or main reason for low FPS I cannot say but would be one hurdle to overcome first anyway.

you simply need to reclaim as much space from that drive as possible.
get CCleaner and see how much it reclaims (be careful, it can install Chrome and/or Avast software depending on setup options and even when they are unticked)
also use cleanmgr from an elevated command prompt.
use cleanmgr /sageset:1 and tick all the boxes.
then type cleanmgr /sagerun:1

then you should turn off hibernation to remove the hibernation file by another elevated command prompt powercfg -h off

then you can reduce your Recycle Bin size and empty it.
and remove Restore Points.

if free space is still tight you simply have to be ruthless and remove unused software and delete (or move to external drive) large movies, picture/music library - that sort of thing.

get WizTree from here; https://antibody-software.com/web/s...using-the-most-disk-space-on-your-hard-drive/
and it'll show you the folders using the most size.

Any update burabotti?