I have been told that after deleting the cache the files will still be on your computer somewhere, If this is the case then surely your hard drive would fill up?

 

I think what you may be refering to is the fact that when you delete files from a computer they are only flagged that they are deleted as opposed to properly removed (I'm not talking about how the recycle bin functions).

Although these files are technically still on your computer and with the right no-how/software can be recovered, they are not actually taking up any HDD space. The space that they currently occupy will gradually get written over as new files are added to the system.