0x8007064c - Error Code Updating Definitions

[Guest]

With this error code 0x8007064c it states "Windows Defender was unable to
complete the update. The installation source for this product is not
available. Verify the source exists

Prior to the update it said I had 176 definitions. So I fear I'm really
suspectible.

Anyone one have suggestions as to what I should do to fix this and get them
downloaded?

 

[Guest]

Try going to WU/MU first to determine if this is a software updating issue
vs a Windows Defender bug...

http://update.microsoft.com/microsoftupdate (and click on express)

 

[Guest]

Microsoft Update initialized
I selected Express

Has 2 - update one had to do with notifications.
Apparently it's to do with Windows Update. KB905474 and KB915597

I am going through with this installation first.
It appears that now the issue is fixed, after running Windows Update.
So it doesn't work with automatic downloads.