Hyper-V no longer working

Happy New Year!
I have been using Hyper-V on a W-10 Pro 64b with two virtualized OS a] Windows XP-SP3 b] Windows 10 Pro satisfactorily, in a Lenovo laptop P70 (Xeon 2.8, 64GB RAM) with Windows 10 Pro.
Just updated the OS a week ago to v:20H2 built 19042.685.
Today the two virtual OS (XP and W-10) have disappeared from the H-V Manager and the H-V Quick Create is no longer running, giving error 0x8007000e "not enough resources memory".
Resources Monitor shows:
Available= 59092 MB
Cached= 3778 MB
Total= 65395 MB
Installed= 65536 MB
Free= 56850 MB
The virtual programs in Windows features were reinstalled. No Change.

Please advice.
Thanks.

I had that error only once on my older i7 but it disappeared after I reconfigured the VM in question.
But indeed, after upgrading the OS a while ago, I also lost Hyper-V feature and needed to be re-added manually, and yes VMs were gone from the list. Annoying issue. The VMs were recreated since the virtual disks are still there.

Just wondering about you laptop config:
Does Windows PRO work on Xeon CPU out of the box or you need a driver?
https://answers.microsoft.com/en-us/...6-220a4dbb9bd5

Lenovo config page (at time of writing this) gives me an automatic Windows upgrade to PRO for Workstations because Xeon 'requires' it...

But that's a bit aside the main question I know.

In any case, if you re-added Hyper-V features and it still gives errors then it must be a sort of weird config issue since it all looks good. Try to re-configure the VM and re-try with other specs / changed memory / cores, I'm not sure exactly what causes the error.

Railtech said:

Could be the result of antivirus software running on the VM host.

https://docs.microsoft.com/en-us/tro...-hyper-v-hosts

Good point.
In the OP's case antivirus option needs to be clarified indeed.

In my case I was on W. Defender only so it doesn't apply but I still had the error, just once. Note to check, I wasn't using the default virtual machine - virtual hard disk files directory because I needed the VMs on a separate disk for more space. Reconfiguring the VM and restarting it solved it in the end.