[ken21]

i had firefox on vista and xp with no problems.

when i purchased and installed firefox,

it crashes.

[raybbr]

i had firefox on vista and xp with no problems. when i purchased and installed firefox, it crashes.

I am assuming you meant when you installed 7?

Did you install 7 as an upgrade to XP or was it a clean install?

The problem is almost certainly not FF.

[AlanD]

Try Chrome instead.