Virtualization vs. Hibernation Question

On more than one occasion, several years ago, I've had Dell laptops "fail" to go to sleep when lid was closed, resulting in battery damage. I also noticed that laptop(s) would still lose battery when in "sleep." For those reasons I prefer "hibernation."

I decided to repurpose the much older laptop for my kids' use and found that hibernation would not enable after upgrade to 24H2. It took a little while to find others with the same issue...attempting to enable hibernation resulted in a "hypervisor" error that prevented it. I did not find Hyper-V enabled from within Windows but someone with the same issue said to disable virtualization in the BIOS. I did that on the older laptop and it worked...hibernation option was restored. However, when I checked on my newer 11th Gen laptop hibernation is enabled in Windows and virtualization is enabled in the BIOS.

Can someone please explain what is going on between virtualization and hibernation...and why the older laptop needs it disabled and the newer one doesn't? Thanks.

a very simple explanation as a rule of thumb.

virtualization saves to Ram
hibernation saves to Disk
or a combination of both.

please check
control panel > power options

on the left panel
'change what the power buttons do'

in this window
'change settings that are currently available'

disable/untick
'fast start up'
a re-start maybe required.

then check the system to see if the required hibernation works.
best of luck, Steve ..