Windows Defender Out of Date & Won't Update after Windows 10 Upgrade

I've been using Windows Defender -- updating and scanning fairly regularly since last February. After upgrading to Windows 10 yesterday, Defender showed up as out of date -- last updated in July. When I tried to update it from the Desktop App, it repeatedly failed. When I tried to update it from Windows Updates, none of the updates (including Windows Defender) would download. After rebooting and trying again-- more than once --most of the updates did download, but not Windows Defender and also an HP Update. Finally, after rebooting and trying again, they began to download, but did so slowly and seemed get stuck (e.g. at 50%). After continuing to reboot and restart the update, the percentage of the download at which it would seem to "stick" continued to rise (75% 83% 90%) until finally-- after rebooting and restarting the update several time --I managed to complete the download of the update and install it successfully. I am running a scan as I type this and the desktop app show windows defender as fully updated. Not sure what all this means, but none of the other help threads that I found via google directly addressed my problem so I wanted to document this for anyone else who is having similar problems.

It's taking a while for the updates lately. Sometimes they go at normal speed, other times it takes time. My last update took over 1/2 hr to d/l, coming in small segments like you described, whereas the one before that took about 5 mins. Just give it time when it seems to "hang up," let it continue.

Might want to run an SFC to see if all is well with your OS.

If SFC could not fix something, then run the command again to see if it may be able to the next time. Sometimes it may take running the sfc /scannowcommand 3 times restarting the PC after each time to completely fix everything that it's able to.

SFC Command - Run in Windows 10 - Windows 10 blog

It's taking a while for the updates lately. Sometimes they go at normal speed, other times it takes time. My last update took over 1/2 hr to d/l, coming in small segments like you described, whereas the one before that took about 5 mins. Just give it time when it seems to "hang up," let it continue.

Thanks--I was able to update the definitions from the desktop app this morning (very quickly--no hangups). Also, whereas my initial "full scan" -- i.e. the first one after the upgrade -- went very slowly (took a few hours), the one that I am running this morning (just as an experiment) seems to be going much faster (already a 1/3 of the way through after just 15 minutes). All is well as far as I can tell...

Might want to run an SFC to see if all is well with your OS.
SFC Command - Run in Windows 10 - Windows 10 blog

Those instructions are a bit complicated (and the command prompt says I need to be an admin running a console session or something to that effect). Is there a simple "for dummies" way of doing this -- at least a provisional first step -- that might reveal some possible problems? Thanks again...

Those instructions are a bit complicated (and the command prompt says I need to be an admin running a console session or something to that effect). Is there a simple "for dummies" way of doing this -- at least a provisional first step -- that might reveal some possible problems? Thanks again...

No problem, scroll down to Option Threeon the tutorial & follow the instructions. You launch an elevated command prompt & type sfc /scannow. Allow it to run, it could take a while. Run it 3 times if it finds anything wrong. Here is a tutorial for launching an elevated command prompt.

Elevated Command Prompt - Open in Windows 10 - Windows 10 blog

If SFC could not fix something, then run the command again to see if it may be able to the next time. Sometimes it may take running the sfc /scannowcommand 3 times restarting the PC after each time to completely fix everything that it's able to.

After that, if you want to view the log scroll down to Option Five, copy & paste the code to view it.

When SFC runs in Windows, it logs it's actions into the C:WindowsLogsCBSCBS.log file. The steps in this option will show you how to see only the specific SFC entries with the [SR]tags in this CBS.log to not have to see all the other unrelated entries in the CBS.log.

Yeah, the slow update thing started with the release of 10, & I was wondering for a while WTF was going on with the updates myself. Did some investigating also & thought it was something on the OS. Started to see after 3 or 4 updates it was a crap shoot whether you got them slow or at normal speed.

Thanks again -- all is well, or so it appears: