virtualbox.org

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?

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.

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.

Cain57 wrote: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.