Fix: Windows Defender Error 0x80240438

Error 0x80240438 followed by a message stating “virus and spyware definitions couldn’t be updated” is a Windows Defender error usually seen in Windows 8 and 10. The error states that updates have been interrupted. There are two possible reasons for this to occur, the first one is that the windows update servers from where the app is receiving updates is down or is having issues which is quiet common with Microsoft, and the second one is that your router or firewall has/is blocking the connection to the update server.

If it’s a Microsoft issue; nothing can be done other then waiting and it should fix itself. If it is a firewall issue then you must check / troubleshoot your firewall.

Troubleshooting your Firewall to fix Error 0x80240438

The first approach i always take is to disable the Firewall entirely. This helps me check if it is indeed a firewall issue before doing anything else and in most cases disabling it fixes the issue.

You can easily disable third party firewalls by pointing your mouse to the av/fw icon on the bottom right and doing a right click. When you do that; you will get the options to choose from; use the one that says disable. These are generic steps that applies to most of the anti-virus software’s with firewall.


If this fixes your issue; then re-enable firewall without doing anything else. Otherwise; proceed to the new method below.

Reboot your router

Sometimes your router can also block the connection to the update server. I always recommend doing a power-cycle. You can do this by turning the router off for 2-3 minutes and then power it back on.

Manually download the update definitions

Microsoft has a way to download updates manually. Since everything is described here. You can easily follow the steps by visiting the link.

Kevin Arrows
Kevin is a dynamic and self-motivated information technology professional, with a Thorough knowledge of all facets pertaining to network infrastructure design, implementation and administration. Superior record of delivering simultaneous large-scale mission critical projects on time and under budget.

Expert Tip

Fix: Windows Defender Error 0x80240438

If the issue is with your Computer or a Laptop you should try using Restoro which can scan the repositories and replace corrupt and missing files. This works in most cases, where the issue is originated due to a system corruption. You can download Restoro by clicking the Download button below.

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