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firefox becomes very sluggish after several hours of usage

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In the past 2 weeks, after several hours of use, firefox becomes very sluggish. Cannot switch tabs easily. Cannot type emails easily, etc. If reboot computer, works fine at first, but again, after several hours, becomes sluggish again. This happens to both my computers which are on a network. A technician suggested a virus, but have not seen any virus messages. Use AVG 2013 virus software.

In the past 2 weeks, after several hours of use, firefox becomes very sluggish. Cannot switch tabs easily. Cannot type emails easily, etc. If reboot computer, works fine at first, but again, after several hours, becomes sluggish again. This happens to both my computers which are on a network. A technician suggested a virus, but have not seen any virus messages. Use AVG 2013 virus software.

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A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:


Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.