Windows Defender - Virus and spyware definitions couldn't be updated

Hi,

Since you’ve encountered the same issue with installing Windows Defender virus and spyware definitions, we’d like to verify if you have done all solution provided on this thread? If you haven’t done it yet, please do so and then let us know if this works for you.

Regards.

Same issue here.  10 pages now and no real answers.  My last successful update was on 10/30/17.

I have tried everything suggested...which was very little.  Most replies were people with the same problem.

When did Windows Defender (WD) update? What virus definitions are currently installed? https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes  

See Troubleshoot Windows Defender Update Issues in Windows 10

The behavior you are describing may occasionally occur if another antivirus program is installed or there are remnants of a third party antivirus program still installed.  

See the Answer of [quietman7

• MVP](https://answers.microsoft.com/en-us/profile/dbf2eeab-ecb2-40e3-8dfe-25191b0dbb6e "quietman7 - MVP")  in https://answers.microsoft.com/en-us/protect/forum/protect_defender-protect_updating/windowsdefender-wont-turn-on/c502c63f-2ffe-4cfd-8b6b-bdfd086cfae0

If the issue continues you may want to try the steps recommended in Problems starting Windows Defender in Windows 8/8.1/10 to include (but not necessarily limited to) running SFC, scanning for malware and running the software removal tools for any security software (AVG, Kaspersky, McAfee, Norton, whatever) that may have previously been on the computer (to include a trial version of McAfee or Norton that might have been on the computer when it was new) followed by a reboot:  List of anti-malware product removal tools

You might also want to review http://www.howtogeek.com/220232/how-to-use-the-built-in-windows-defender-antivirus-on-windows-10/   Good article but ignore the ads!

Or

If WD still does not update, wait a few hours and try again to manually update the program….remember WD normally should automatically update every 24 hrs if an update is available and the program needs to be updated. 

Alternatively - - -

You may prefer to install a third party antimalware program (which should disable Windows Defender).

There are a number of viable free and paid options available – take your pick…

Choosing an Anti-Virus Program

Is Windows Defender The Best For Windows 10?  Good article but ignore the ads.

http://windows.microsoft.com/en-US/windows/antivirus-partners#AVtabs=win10

Regards…

http://blog.emsisoft.com/2015/01/27/top-10-ways-pups-sneak-onto-your-computer-and-how-to-avoid-them/

I have tried everything suggested...which was very little.  Most replies were people with the same problem.

Window defender Virus and spyware definitions couldn't be updated.