Updating Firefox does not delete your history or other user data.

except when it does... support.mozilla.com/questions/808979 ok mean character is off now, but it's still a huge deal to me to get my history back. i have the places.sqlite file from 3.6 to somehow extract data from into 4.0 but i'm not proficient with LITA enough yet. i really don't care that history slows things down. i much prefer having it there to allow me to get a quick reference into what that site was i visited last year for that struggling start-up company (or whatever.)