See Firefox is already running but is not responding, which should help you solve that problem. Once that's all set, you can try downloading the update directly from firefox.com.

Hi Nic, restarted the computer and went to the profiles folder without opening FF but there was no parent.lock file to delete Mark

second request

an auto update failed a few days ago and now everytime I open FF I get an error message that says can't install update, firefox is already running, but it is not! the parent.lock file is not open when FF is closed in addition to this message, a box opens asking looking for a file 

Help!

Do you have more than one User Account on your computer?

I had this same problem ..error message: can't install update, firefox is already running, I had another user account which had firefox open. Once I closed this I was able to update no problems.

no smiley, i only have one user account. and I checked the task manager to make sure FF was closed. thanks

hi I had the same problem (update failed for normal user, update worked for administrator, but then normal user still got asked about installing the update even though it was already done). Following the advice on http://kb.mozillazine.org/Software_update#Software_Update_not_working_properly worked for me, in particular to remove the update-related xml files.

good luck

kris