virtualbox.org

I have been using Ubuntu in VirtualBox. But for the past few weeks I couldn't boot the Ubuntu (both 18.04 and 20.04). After removing the guest, new guests showed errors in files. But I verified with checksum and no errors were there. So I uninstalled VirtualBox. But while reinstalling the same, the installer was not responding and in the end it showed like "Installation failed! Error: Fatal error during installation".
My system is Dell Inspiron 5575 with Windows 10 2004 version
I also have WSL2 installed.

AsifAli wrote:I also have WSL2 installed.

That'll do it. WSL2 requires Hyper-V and Hyper-V blocks Virtualbox.

The devs are trying to get Virtualbox to run with Hyper-V. The new test builds might have a fix for this problem. If you try a test build and it works, report here: viewtopic.php?f=6&t=90853, and save the installer file.