When I try to generate surface textures from the file menu, an error pops up saying

"Pak File Error!
Cannot Open pak file Level.pak for writing. Attempting auto-fix!"

Then says

"Export Failed!
Cannot Open pak file Level.pak for writing. Attempted force full overwrite failed!
Please check that you have permission to access the file on disk and contact a sandbox / tools programmer!"

------------------------------------------------------------------------------------------------------------------------------------------
When I try to make a new level by the file menu this pops up

"Failed to create level directory: gamecrysis2\Levels\<map name>
Error: Access is denied.

Current Path: C:\Program Files 9x86)\Electronic Arts\Crytek\Crysis 2"

How do I grant myself permissions? And where would I go about doing it?

Thanks in advance. Maximum confusion
And yes I am a Noob at these things

Assuming that you are running windows 7 have you tried running Sandbox as an administrator? Right click the sandbox icon and select run as administrator...

Hahaha, never thought that you would still have to run it as an admin if you are the admin, thanks fixed it