New windows update messed up my virtualbox, need help

[Carl1041]

Hello guys. For a bit of context, I have a windows 10 host and guest setup. Yesterday everything worked perfectly, until today, after I installed the new 20H2 update.

When I boot up my windows 10 guest virtualbox, the CPU shoots up to 100% after the blue windows watermark shows up. I let it run for an hour but its very very slow.

Is there anything I can do to try before heavily-troubleshooting it? Maybe the recent update messed something up?

[scottgus1]

Please right-click the guest in the main Virtualbox window's guest list, choose Show Log.

Search the far left tab's log for this text:

Attempting fall back to NEM

If you find it, Hyper-V is enabled. See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

If you don't find that text, save the far left tab's log, zip the log file, and post the zip file, using the forum's Upload Attachment tab.

[Cain57]

Same here. It made my VM screen some tiny resolution, I could not fix. Just deleted and reinstalled everything and an older version of Windows 10.

[scottgus1]

deleted and reinstalled everything

Usually, nuking from orbit is not necessary. A new topic on the forum with a descriptive explanation of the problem and a zipped vbox.log posted using the forum's Upload Attachment tab often provides for easier solutions.