Moving Firefox Profile to another drive or directory: How-to
In many organisations a user's Profile size is restricted to a certain size and there is a constant juggling act to try and keep under your Profile quota. Firefox is an example of one application that was taking up lots of space in my quota, but I found that there is a nice and easy way to relocate the Firefox Profile to another drive or directory. Check out Mozilla's Step-by-step instructions for how to do this. This worked fine for me using Firefox v3.0.8 on Windows XP.