Windows Defender Antivirus taking a long time to install definitions

Windows Defender Antivirus is talking a long time to install new definition updates.

The typical time is 30 minutes but it can also take 40 minutes, 1 hour or 2 hours. Today it’s taken 8 hours for the first time, which coincides with the Protection History in Windows Defender Antivirus being unexpectedly completely blank losing the data that was there.



It seems like the performance of Windows Defender Antivirus is gradually degrading over time. I’m now forced to go back to my preferred Antivirus, Comodo Internet Security because that problem was severely slowing down my computer.

Especially as there can be six of these definition updates outstanding to be installed in one day. This made me unable to get any work done on my laptop as I would wait hours for the definition to install in order for me to continue whatever it was I was doing on my laptop.

It’s just that windows technical support forums often ask users with strange functionality issues and performance issues that would be difficult to identify the cause, operational discrepancy or solution, to uninstall any third party antivirus as forum users do not have the privilege of being in the physical proximity of the OP’s computer or even to use it normally on a daily basis.

Notice how in the video below, that after clicking the "review" button, I am taken straight to the Protection History page that is blank when it shouldn't be. The only workaround for this is to visit the Antivirus home page the look under the Current Threats header.



I’ve tried using dism and sfc and that didn’t work. Doing an in-place repair to reinstall windows didn’t work either. I'm using Windows 21H2

Hi @desbest

Through this link you should find some valuable solutions (Microsoft community site). I’d say have a go at the ones that look most convincing to you first then look at the less likely ones (you never know, those could be the fixes!)

Have a good evening,

-James

> A few good options here

You most likely have issues with Windows update, not windows anti virus