Blatantly stolen from Jussi Palo’s post here, and archived here.
All credit to the original author.
Challenge
Time to go all in with Windows 8 and migrate development environments to Hyper-V.
When you’re migrating from VMware to Hyper-V, and you happen to install Hyper-V before uninstalling VMware Workstation or Player, you will get warning that VMware cannot uninstall while the Hyper-V role is installed on the machine.
Solution
Modify the file C:\ProgramData\VMware\VMware Player\Uninstaller\bootstrap.lua, or C:\ProgramData\VMware\VMware Workstation\Uninstaller\bootstrap.lua using a text editor. You may have to run that editor as an administrator and then open the file from within it.
Comment out the line:
CheckForMSHyperV()
…with two dashes, leaving it as:
--CheckForMSHyperV()
Save the file, and attempt to uninstall VMware again.