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How do I stop DEP closing firefox


After downloading "Trusteer" as recommended by my online bank, I noticed that everytime I went online via Firefox, after a certain period (not always the same time period - it varies) DEP forced Firefox to close. I have tried to change the DEP settings via: Control Panel/System/System/Properties/Advanced/Performance/Settings/Data Execution Prevention.

I have tried both of the options shown and the problem remains.

Additional System Details


  • User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; Sky Broadband; Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) ; .NET CLR 1.1.4322; InfoPath.2; McAfee; yie8)

More Information

Wesley Branton
  • Top 25 Contributor
178 solutions 2062 answers

It sounds like DEP doesn't like Firefox!

Ensure that you downloaded DEP from the official source and not through a download mirror.

Can you change the settings to allow Firefox full access to the internet and your computer?

  • Top 10 Contributor
  • Moderator
10745 solutions 96691 answers

Do a malware check with some malware scanning programs on the Windows computer.
Please scan with all programs because each program detects different malware.
All these programs have free versions.

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

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

See also:

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