Can't install Fortnite on old PC that used to have Epic installed

Finally came home to old pc - didn't realise Epic was still installed from 2020. Tried to install Fortnite last night which for some reason started on 58%- tried to run today and crashed on open. Repair just did the instant thing where it goes done instantly and i'm like, that was too fast no you didn't. Uninstalled epic launcher and tried to uninstall Fortnite and remove any traces- now I can't reinstall Fortnite. Heroic claims 0B disk space- it has 150gb free, and if I change dir from games/heroic and back it says "may not be writable". huh??? If I force install it starts on 58% then force stops install for some reason. Tried using CMD and got a strange error- I suspect Epic related- nuked all traces of Epic i could find and reset Heroic to no avail. Also tried CMD incase it was still considering it an old install- probably had it installed on epic. please help i don't want to have to wipe the pc to get it to work it's got old stuff on :( bonus picture of the funny error I got from trying to reset heroic incase it was somehow seeking epic files that weren't there anymore. thanks. i don't care if i am called a fool so long as I can get it fixed.