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Firefox is very slow after reinstall - tried all troubleshooting

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I have been using Firefox for many years and never had issues. Two days ago, I turned on my HP with Windows 10 and I got a pop up message something about Error Platform 126.0 XUL Runner is not compatible. I could not access Firefox, Google, or the internet. I uninstalled Firefox and reinstalled, but after that, everything runs very slow. Each time I go into a website, it can take up to over a minute to pull up! I cannot even delete email from my Gmail! It's piling up. Downloading can take over an hour! I checked all the trouble shooting forums in Mozilla and tried just about everything. I went back into "About:profile"s and created a new profile. It it did not make any difference. I also did a Firefox refresh. Did not help any. I went back into the profile I had before the XUL error because my bookmarks were there. Still slow. I cleaned out the cache, in both Firefox and my Windows 10. made no difference. I only have three extensions in Firefox. I don't know what else I can do to fix this. Also, my drivers and other software are automatically updated by Windows. My HP is only 2 years old as well. Everything was fine in Firefox until that XUL error message popped up and I had to uninstall and reinstall Firefox. That is when everything became agonizingly slow!

Update: My computer is barely usable anymore because of the Firefox issue. Having to wait for a minute or more for everything I do on the internet? I know it cannot be my computer itself because it is not even two years old yet. I may have to dump Firefox if I cannot get this fixed. I have Norton 360 and it is not malware or a virus. Firefox messed something up.

I have been using Firefox for many years and never had issues. Two days ago, I turned on my HP with Windows 10 and I got a pop up message something about Error Platform 126.0 XUL Runner is not compatible. I could not access Firefox, Google, or the internet. I uninstalled Firefox and reinstalled, but after that, everything runs very slow. Each time I go into a website, it can take up to over a minute to pull up! I cannot even delete email from my Gmail! It's piling up. Downloading can take over an hour! I checked all the trouble shooting forums in Mozilla and tried just about everything. I went back into "About:profile"s and created a new profile. It it did not make any difference. I also did a Firefox refresh. Did not help any. I went back into the profile I had before the XUL error because my bookmarks were there. Still slow. I cleaned out the cache, in both Firefox and my Windows 10. made no difference. I only have three extensions in Firefox. I don't know what else I can do to fix this. Also, my drivers and other software are automatically updated by Windows. My HP is only 2 years old as well. Everything was fine in Firefox until that XUL error message popped up and I had to uninstall and reinstall Firefox. That is when everything became agonizingly slow! Update: My computer is barely usable anymore because of the Firefox issue. Having to wait for a minute or more for everything I do on the internet? I know it cannot be my computer itself because it is not even two years old yet. I may have to dump Firefox if I cannot get this fixed. I have Norton 360 and it is not malware or a virus. Firefox messed something up.

Modified by history1962

Chosen solution

I think the problem is fixed. This morning I decided to disconnected the internet, waited 20 seconds and reconnected. Everything seems to be working now. Strange how removing Firefox and reinstalling it would effect the performance of my internet provider. If anyone else has this similar problem after trying all the other troubleshooting, disconnect your internet and and reconnect again.

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Chosen Solution

I think the problem is fixed. This morning I decided to disconnected the internet, waited 20 seconds and reconnected. Everything seems to be working now. Strange how removing Firefox and reinstalling it would effect the performance of my internet provider. If anyone else has this similar problem after trying all the other troubleshooting, disconnect your internet and and reconnect again.

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