I'm having trouble installing mods since I reinstalled windows. Zip programs and Nexus mod manager won't unzip there files.. it keeps coming back as an error. How do I change permissions so this does not happen?

If its an admin rights error you could try ;

Right click on zip program and/or nexus mod manager,
Chose properties and go to the compatability tab,
Tick the option to "run as an admin" and apply.