I'm trying on windows 8.1 now and can't get a simple ping probe to work. It seems that windows 7 or earlier are most compatible, so gonna stick with that for now.
Thanks for comments.
In order for ping probes to work, the user the Dude service is running as
must have Local Administrator access on the machine.
If you're running the Dude with its default installed options, it tends to run in the context of the user that first opened the program. If you want to put it in "Run Mode: as service" mode via the Local Server button in the top/left, you need to have the Dude application opened as Administrator (UAC Escalated mode). Once you've installed it that way, the default run as service account runs as LOCAL SYSTEM, which is an elevated account and should work for ping probes.
At my office, we try to avoid LOCAL SYSTEM services whenever we can to minimize potential security risks, so we set up a separate service account for the Dude's service user. In that case, we have to manually add the service user to Local Administrators, or ping probes and other elements that require escalation will not work (e.g. writing to the Program Files directory, if you installed via the default options).