Question: How can I turn a given normal application into a Windows service under Windows XP?

EDIT: This is a server application, so it has no GUI and does not require any input or output.

Answer: 
Use [SRVANY.EXE](http://support.microsoft.com/kb/137890) from Windows \* Resource Kit

For Cygwin applications Use [cygrunsrv](http://cygwin.com/packages/) (NT/W2K service initiator)
[FireDaemon](http://www.firedaemon.com/) is another option for doing this.