Q: Is it posible to wipe a mac but keep certain files

Get the files you want off to a secure location - preferably backed up twice

Then reformat your hard drive

Then put those files back

What is other and what can I do about it - Apple Support

Before wiping your computer:

Try downloading and installing OmniDiskSweeper:  OmniDiskSweeper

OmniDiskSweeper will sort your files by size and show you where they are located.

See the following video on OmniDiskSweeper. Using OmniDiskSweeper

You can then copy some of the bigger files like videos, etc. to an external hard drive to free up space.

Kim

1. backup the files that you want to keep
2. erase your mac and reinstall os x
3. put the files back