Fix: Windows Defender error 0x80004004

Originally published at: Fix: Windows Defender error 0x80004004

The Windows Defender program is a great security service provided by Microsoft in Windows. In Windows 8 and Windows 10, Defender has been improved significantly, and now it can be used as a stand-alone antivirus program. Windows Defender is a freeware tool provided by Microsoft in Windows 8 and Windows 10 for the purpose of…

I cannot help you troubleshoot the issue here if you’ve already followed everything listed in this guide - I wish i could, but it will take a lot of time going back and forth replying trough comments and keeping track of it. I thought if we can resolve this remotely, i’ll post the details of the fix in this guide.

Possible. Can you connect to a fiber or other high speed internet at friends place or somewhere to test?

Find the file Program FilesWindows DefenderMSASCuiL.exe then right click and run as Administrator

No, we ought to be able to do that here. Without me giving up any personal information, and publicly, so everyone else with the same issue can see the results for themselves.

I can help you troubleshoot the issue directly. Please send me an email on

if this is the case next time before you uninstall a program use Revo uninstaller… as you uninstall things it digs into your computer for left over registry keys pm the program you are trying to remove. and removes them as you tick what is in the bold

I’m on Windows 8.1 and I tried doing the equivalent by going to the Settings tab in Windows Defender and unchecking “Turn on real-time protection”.

I’m not running any other AV software but if that worked for you it sounds like Windows Defender was defending against its own updates.

I was able to fix my problem Windows Defender (0x8004004) whose signature antivirus does not want to update. Once assured that this is not a virus or a conflict with an antivirus or antispyware. Here is what I did to solve the problem under Windows 10:

Start (bottom left)> Settings> Go app Update and security> Windows Defender> Real-time protection> Disabled.

Now that Windows Defender is disabled you can update your antivirus signature. Once done, you reactivate the protection in real time on your window of applications Windows 10. You do the same by activating on Windows Defender.
Normally everything should come back in order.

Salam aleykoum.

Instead of telling him what you think he means, why didn’t you attempt to resolve the issue?

You’re stumped too…

I have the same issue. I’ve been having the same issue for weeks now. No other AV programs, 31.7mbps down, 7.8mbps up.

I have yet to find a reliable solution.

See if left overs of previous AV software are there?

I have tried all above and still can not update security essentials. Tried safe mode with networking and still didn’t work. Windows Defender shouldn’t be running when you have security essentials installed. I keep getting the error message 0x80004004. I have no other AV software running on my machine. I have full internet service. What is going on?

You mean, you cannot update Windows Defender.

I have windows 7 and can’t update my update . Error OX8004004. My connection does not appears to be bad.

tried all that - I use a satellite internet connection so maybe that is a problem (latency?)