Unable to open kernel device “.\Global\vmx86”:The system cannot find the file specified. Did you reboot after installing VMware Workstation?

This recently occurred on my system and although the cause is not yet know, the fix was pretty simple.

Open command prompt (Win+R) but ensure it is run as admin, try net start vmx86, it will probably fail but at least you’re not doing unnecessary steps. Now (still in cmd prompt) change directory into the Workstation install location and type vnetlib — uninstall vmx86 and reboot your physical host machine.

Open command prompt again and type vnetlib — install vmx86 then reboot again, this time the issue should be gone and you can run the VM’s as normal.

If you still have no luck then try reinstalling workstation.