Symptom: Firefox takes awhile to come up in Windows XP. It further takes awhile to load my start page. Symptom: Open up a Google search results page, click my first choice, it's taking too long; I close that page and select a second choice and it loads right away. This doesn't matter whether I chose the top choice, second or third choice first, and another choice higher or lower in the list as second choice. I've been running Spybot Search and Destroy, Ccleaner, and have the Microsoft Essentials for anti-virus. I have been using the Auslogics DiskDefrag to optimize and defrrag. SOLUTION: I downloaded and ran the full file scan of Malwarebytes (Trial), which required a computer restart when it was finished, having found four Trojans plus all of the quarantined files set aside by CCleaner. I deleted everything in the list, and restarted Windows (first time). I ran another full file scan with Malwarebytes and found four files. Nothing in memory, nothing in the registry. I deleted these and restarted Windows the second time. Now Firefox comes right up, Google opens up in the first tab right away, I open the new tab and select Gmail and it comes right up without delay. My issue with slow Firefox response time was malware. One of the malware was a player setup that I recently downloaded ... can't off the top say which player that was. It may have been infected at its source, or it may have become infected on my computer upon arrival here. I post this "question" as a report on the solution I found for a slow-performing Firefox. My first issue with a slow Firefox came after a series of events, which I will try to recall here: I had a decent response from Firefox. I downloaded and ran Auslogics DiskDefrag, After optimizing and defragging, I still had good response from Firefox. I downloaded a dirty file, I can't say from where. I downloaded Auslogics BoostSpeed, which scans something like five categories and allows the free cleaning of one category. Without purchase of a license, this product is limited to cleaning the first-chosen category from this time forward for free. I chose to clean wasted space.from the several first-time options available. I now had a sluggish Firefox. I got rid of BoostSpeed. I am not accusing anything here, but I was searching for a cause. I had run Spybot S&D, CCleaner, AdwCleaner, and was using the Microsoft Essentials. for AV. Still a sluggish Firefox. I ran the two full file scans plus restart using Maywarebytes (Trial) and Firefox is fast coming up, loading Google, and responding to my selection in the new tab. Many folks are complaining about Firefox being slow. I found out the reason in my case why it was. Edited to remove some typographical errors and modify some choices of wording. And Thank you, SuperSluether. Oh. Add-ons I have in use: Memory Fox 7.4 -- in its Options nothing selected with a checkmark, and wait times set to minimum RAMBack 1.0 (there are no options) Memory Restart 1.16 -- this add-on minimizes Firefox memory usage when it hits a threshold of 229MB, shows a red button if I am over, green if I am under. Original value for the threshold was 500MB, that was too high for me. These three add-ons are really a lifesaver and keep Firefox from locking up system memory and bringing the computer to a crawl. With good management of memory, I also have less issue with scripts not responding. I can actually stay tuned to a YouTube playlist. I highly recommend these three. .