If a slave name has a space in it, the service cannot start. It created an
element of XML like this:

<arguments>-Xrs -jar "%BASE%\slave.jar" -jnlpUrl
http://build.gotgenie.com:8090/computer/Windows XP VM/slave-agent.jnlp</arguments>

so the jnlpUrl will only be "http://build.gotgenie.com:8090/computer/Windows"
and the slave jar will get the rest as more arguments, failing the service.

I tried quoting the URL, which allowed the service to work, but the slave never
showed up online after a few minutes. I unquoted it, swapped the spaces with
%20, and restarted the service and the slave showed up instantly.