If you have a VMware ESX cluster running some Windows VMs, you’ve probably noticed very poor mouse response when on the console of your VMs. The fix is actually very simple. You need to bump up the hardware acceleration in the display preferences. You can either do it from the GUI (right click desktop -> properties -> settings -> advanced -> troubleshoot), or you can do it from Powershell:

set-itemproperty -path (((get-itemproperty "hklm:\hardware\devicemap\video")."\Device\Video0") -replace "\\Registry\\Machine","HKLM:") -name "Acceleration.Level" -value 0

What this command does is query the HKLM:\Hardware\Devicemap\Video registry branch to find the true location of your primary video device, and then sets the Acceleration.Level key to a value of 0.

The only problem with editing the registry setting directly is that Windows doesn’t automatically reload the display configuration, so the change doesn’t immediately take effect. Although it is technically possible to do that from Powershell, it isn’t easy (requires p/invoke) and you’re probably better off just rebooting the VM. :)