I have a sound I like to set for the new message notification in Thunder Bird. In TB options I just set it to use the sound. On my normal install this is no problem. On portable TB I set the path to the file but the drive letter will change depending on then machine I am on. So if I set the path as F:/Documents/gmail.wav it doesn't work if I am on a machine that designates my thumb drives as another letter other than F. Is there a way around this?