Here's a couple of AutoIt scripts I knocked up for Firefox 1.5.0.1 and Thunderbird 1.5. They both do straight forward installs, no error checking, just a clean install. Fine on a PC with no existing software. Please note: These are coded for the EN-GB versions, so look for 'Licence' not 'License'. You might have to change those bits for the EN-US version. Hope somebody finds them useful! Firefox1501.au3 Thunderbird15.au3