Not once i have been asked how to create a new service for the subversion aka svn server in windows.
So, the solution in command line is very simple:
sc create Subversion binpath= "c:\SVN\svn-win32-1.6.2\bin\svnserve.exe --service --root c:\SVN\Repository" displayname= "Subversion" depend= Tcpip
displayname = can be anything
Hoped i helped a bit,