Recently came across a problem when trying to access a parallel port dongle from a Workstation machine.

The VM was configured with a virtual parallel port, and the host machine had a PCI parallel port card installed which was recognised by the host OS (Windows 7 in this case).

Every time the VM was started, Workstation threw an error along the lines of:

Cannot open VMparport driver for LPT3:
Failed to connect virtual device parallel0

After looking round the VMware Communities for a while, I found the solution.

The PCI Parallel Port card was installed after VMware Workstation. During the Workstation installation process, the installer looks to see whether the host has a parallel port, and if it does it installs a driver allowing VMs to access the port. If there’s no parallel port, the driver doesn’t get installed.

The problem here is that if you add a parallel port afterwards, there’s no virtualisation driver for it, resulting in the error above.

The solution is to uninstall and reinstall VMware Workstation after the hardware change. Reinstalling doesn’t affect any settings or VMs as long as you tell the uninstall process not to delete anything.

This probably applies for VMware Server and Player too.