delete this

[VillaiNPC]

I've been building up a lot of useless files over time and really can't be bothered to go through my whole PC and manually delete them. I have clean installed my PC a few times but this time I'm torn on which option I should choose, I've always wondered what the "personal files" actually are as I don't have any idea and if I was to clean install what would I have to do to get things up and running again or is it just the same as the first option just without keeping personal files.

[DDOking]

personal files from what I understand is stuff thats installed on the OS drive it self. other then that I got NO IDEA

[ChristopherH]

Generally, you want to perform a clean install every 12 months. Unless you are an advanced user and change folders to funky locations, you usually only need to backup your Desktop and Documents folders (in C:\Users\<username>\ directory) to external media, then format the HDD/SSD and reinstall. Otherwise, best to create an image of your PC in case you miss some files that you should have backed-up prior to doing a clean install.