Date: 2014nov4 Product: Adobe Premier OS: Windows Q. Where does Adobe Premier keep its cached files? A. By default On Window it uses:

C:\Users\[username]\AppData\Roaming\Adobe\Common\Media Cache Files

You can change this in Premier from:

Edit > Preferences > Media > Location

There is also a "Clean" button there. I have found that button doesn't delete everything. So you can exit Premier (and other Adobe programs) and delete all files in that folder using Windows File Explorer.