Can the dude monitor services on a Windows machine? I know we can design custom services and probes but I don't know where to begin. I just want to be able to monitor certain services on some computers to see if the service is running or not running.

If you search the forum for a topic called the "probe thread" (or "probe topic") you can find an example there how to built a probe that checks if a certain program is running or not. From there on you could probably manage yourself to adapt it to check for a service (instead of a program), if that is possible at all, of course (if that info is available through SNMP).