hello nothing is speaking against using windows xp when it is fully patched - however firefox 3.6.20 has reached its end of life nearly three years ago, is unsupported and affected by many dozens of highly critical security vulnerabilities!

please Update Firefox to the latest release immediately & see if this also can address the crashing issue.

Hello jalp5dai, be sure that you have xp with sp2 or above, because the new/latest version works only (in xp) with sp2 and sp3, otherwise you are not be able to update to latest version (as correct prompt philipp in his reply)

thank you

I need to know what (if any) updates can actually work on my OLD computer before I even try to download them.

hello, as ideato has pointed out, firefox 21 will work fine on windows xp with sp3! here are the system requirements: https://www.mozilla.org/firefox/system-requirements.html

Sorry, both of you -- and particularly ideato; it seems we were cross-posting while my "Add or Remove Programs" list was populating. I'm pretty sure I have SP2, dunno about SP3 . . . no, wait, I do have XP SP3.

(And now I've cross-posted with both of you. Ah, keyboards -- how quaint my reliance on them is. . . .)

The computer, BTW, is a Presario V5000, if that tells you anything useful. Maybe it will help more if I say (after checking Device Manager) that the CPU is a "mobile AMD Sempron 3300+". Can you tell me whether or not that is a "Pentium 4 or newer processor that supports SSE2"?

Go(in win xp) to Start > control panel > system > general tab and you have all the info you need, service pack (sp) and memory (probably you have memory 512mb or 1 giga), if yes you must update firefox with the method philipp gave us above.

thank you

Hmm . . . I think maybe the CPU is okay, but I would appreciate any time and effort you folks could spare to confirm my work.

Wikipedia lists a "3300+" model twice in its article on Sempron processors. One is a "Socket A (Socket 462)" model named Barton and with a listed 130ns speed. The other is a "Socket 754" model named Palermo with a listed 90ns speed. The latter sounded familiar, but my left hand has worn off anything readable from the sticker next to the "mouse area" so I couldn't confirm it that way.

Checking the properties of the CPU (through my hardware configuration) revealed an interesting ID string which suggested my CPU was "family 15 model 44". And re-searching for that (via Yahoo, since I couldn't risk another Google crash) brought me to a late-2009 AMD Processors forum entry where some other expert answered a question by identifying that family and model as "AMD Sempron64 socket 754, e.g Sempron 2600+, Sempron 2800+, including all latest core stepping versions of desktop model Semprons, socket 754."

If that's correct, and I've followed along the road properly, then my CPU is also in that family, and in that socket -- which would mean it was one of the processors built to work with SSE2. And that, in turn, would mean it should be able to run the v21 of Firefox you mention -- right?

I don't know how much slower or faster v21 may be -- and I won't want to dump even the Mozilla-abandoned v3.6.20 until I see what if any side-effects there may be. But maybe there's an end in sight.

(If you have any hints for me on this score, I would appreciate them. Likewise if you have any idea why it took months of Reporting Crashes before I got any response at all, even from the autobot. But most of all, I would greatly appreciate your help in getting over what may be the final obstacle to finding out if it's possible for me and my old PC to run v21 . . . and in finding out what choices I have if that doesn't work.)

Ah, another cross-posting. Well, it gives me another chance to thank you both . . . and to double-check if ideato's mention of phillipp's "method" for updating meant that I should use the link phillipp provided to go directly to v21 and not try to collect a newer version that I couldn't use.

i don't known if you can see now the next link, but if you update to latest it is useful : Common questions after upgrading from Firefox 3.6

thanks

Well, that may not answer the question I had left -- but it may answer some upcoming questions before I have them. We'll see. Thanks for the suggestion.

The Windows NT 5.1 in your useragent refers to Windows XP.

An alternative is to try the portable version of Firefox 21.0 on harddrive. It may run a tad slower and not use Cache but at least you can see if it works without touching the Firefox Profile you are using win Firefox 3.6.20 (3.6.28 was the last) as everything is contained. http://portableapps.com/apps/internet/firefox_portable

Desktop or Notebook?

If that is a Notebook, look on the bottom for a spec plate, and see what the date of manufacture is.

Your computer should be able to run Firefox 21 totally fine, so long as you have Windows XP service Pack 2 or higher (you should have all windows updates, they don't slow your computer down, and they help it stay secure and stable). After updating windows, install Firefox 21. It'll be quite a bit faster than 3.6

Two more rounds of thanks! -- but a few more follow-up questions, too.

James, I already run Firefox from my hard drive. Or are you suggesting putting it on a jump drive or something else separate from my PC?

And Ed-meister, my PC is a laptop, but I don't see a production date on the bottom. I do see a date of 10/26/2004 on AMD's CPU driver (version 1.2.2.0); does that tell you something I should know?

[UPDATE: I'm running out of time I can spend on this right now. Remember, the only problem I'm having (visibly, at least) is sometimes not being able to use Google to search. And maybe having my browser so busy that I can't do anything else -- or even that, too smoothly. So I thank you all, and I promise I will come back later and look at any more follow-up suggestions . . . but I have to sign off from this now.]

You can install the Firefox portable version on the hard drive.
This version uses its own profile folder and doesn't interfere with other Firefox installation and is thus perfectly to use of check out a new (or older) Firefox version.

You can try to do a malware check with some malware scanning programs on the Windows computer.
Please scan with all programs because each program detects different malware.

Make sure that you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender: Home Page:
  http://www.microsoft.com/windows/products/winfamily/defender/default.mspx
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• http://support.kaspersky.com/viruses/solutions?qid=208280684

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

jalp5dai, I was referring to the portable Firefox at the link I posted. http://portableapps.com/apps/internet/firefox_portable

As Tyler said the Firefox 21.0 should work.