There are a few conditions that need to be set in order to successfully execute a Convert task or any other PDM task, for that matter. By default, PDM does not set up a default "host" to run these tasks and leaves that up to the user. A very common issue as a result is the execution of the task with no defined host available, resulting the the task failing to start and being in a "hung" state.
The first step is to ensure that the computer you would like to run tasks on is defined as a potential task host. This can be done by right-clicking on the Enterprise PDM icon in the taskbar, and selecting "Task Host Configuration."
This should bring up the following window. Make sure the "Permit" check-box is checked, essentially allowing the task to use the computer to execute the task.
Once this is complete, you can then go back to the actual task settings and then locate the computer or computer that were permitted to run tasks.
If your computer or computers do not show up immediately, refresh the list,and they should then be visible. Check the boxes of any computers that you would like to be able to run the task.