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Firefox Crashes when Windows Defender is active.

colombagechamath
colombagechamath
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Firefox is using too much CPU resources when Windows Defender's Real-time Protection is active. I can't even open more than 3 tabs without CPU usage spiking up to between 95% and 100%. Then firefox becomes practically unusable so I have to force close it using Task manager. This problem started recently after I switched from FF 32bit to 64bit on Windows 10 creator's update.

I've tried every possible solution from running FF in safemode to switching back to 32bit version of FF still without any luck. My CPU is a Intel core-i5 with 3.10 ghz.

Firefox is using too much CPU resources when Windows Defender's Real-time Protection is active. I can't even open more than 3 tabs without CPU usage spiking up to between 95% and 100%. Then firefox becomes practically unusable so I have to force close it using Task manager. This problem started recently after I switched from FF 32bit to 64bit on Windows 10 creator's update. I've tried every possible solution from running FF in safemode to switching back to 32bit version of FF still without any luck. My CPU is a Intel core-i5 with 3.10 ghz.

All Replies (2)

Scribe
Scribe
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Hi, try reducing the number of multiprocesses: Go to Options > General - Performance, then deselect 'Use recommended performance settings' and change 'Content process limit' to a smaller number - try 1. See - Firefox's performance settings, and Startup, home page, tabs, and download settings.

You could also install 32-bit Firefox, just select the 'Windows' version and download it from https://www.mozilla.org/en-US/firefox/all/

You won't be automatically changed back to 64-bit again.

If your question is resolved by this or another answer, please take a minute to let us know. Thank you!

colombagechamath
colombagechamath Question owner
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Thanks for the quick reply. However when I try to change the 'Content process limit', it is disabled with a message about "Learn how to check if multiprocess is enabled". Although in the disabled drop-down list there is 1 already selected. And I also tried using the 32bit FF. In fact right now I have both 32 and 64bit versions installed till I can resolve this problem.