Sorry no answers, but a few questions.

• Is anything else changing in that sort of way, i.e. versions changing ?
• What security and backup software do you use ?
• Are you using a multiple user system?
  • is Firefox installed for multiple users

This seems rather unexpected behaviour. I have not specifically searched for such questions, but I have seen another similar one /questions/917897

(I did have multi user Windows XP sytems that do have multiple Firefox installs but they are not in use at the moment.)

Only FF version is changing. Symantec Endpoint Protection. It's Win XP and I'm the only user, other than Administrator which I only use very sparingly.

No one else here at work is having this issue. Nor am I having it on my laptop or home desktop.

The similar one you point out sounds identical to my issue, just reverting to a different old version. I subscribed to that one and will most likely take any further posts there.

Thanks for the help.

Some users have problems where the install does not work. One possible reason for that is security software blocking the download or the install process, however it sounds as if that is not happening in your case.

If your install works, is there any possibility that backup software is restoring the system to previous state?

What happens to the Administrator account ?

• does that also update and run Firefox 10 ok
• does that also change back to Firefox 3.6

If you you obtain the Firefox 10.0.2 installer then delete the Firefox 3.6 program folders (Take care NOT to delete the profiles) then install Firefox 10.0.2 does that produce a proper update that does not revert?

If Firefox 3.6 reappears where are the files coming from?
(Leave Firefox physically offline whilst deleting, reinstalling and re-starting thus preventing any possibility of the files being downloaded)

I waited a few days as the problem was intermittent and I wanted to see what might happen.

Before your post of a couple of days ago I had obtained the FF 10.0.2 installer and stored it locally on our LAN. (Before that I had been using the 10.0.0 installer.)

I used the 10.0.2 installer and reinstalled FF. That was 3 days ago. Since that time FF has stayed at 10.0.2. I decided to push the envelope <g> and reboot this morning. FF stayed at 10.0.2. Hopefully this is the end of it and this version sticks.

I don't want this posting to invoke Murphy's Law. But I do think I will wait a few more days due to the intermittent behavior. If another week goes by, along with a reboot at that time without issue, then I would be ready to say it's resolved.

Thanks.

• RESOLVED*

Another week has gone by without the problem reoccurring. I rebooted again this morning and FF stayed at V10.0.2.

Glad it worked out, thanks for posting back.