|You should be OK with old version 22.214.171.124 for XP from the link given above.|
The current version from Mozilla is 3.2, and the implication is that it still supports XP. However you are definitely likely to need XP SP3 for that, but nobody with XP should be using anything less.
An aside, but probably time to post these two again, which can help XP security:
Always pop back and let us know the outcome - thanks
message edited by Derek