splunkd.exe environment variables SPLUNK_HOME PYTHONPATH etc

Hi I installed Splunk on my laptop (Windows 7 64 bit) and things worked fine . I stopped the Windows service and was playing around with some Python modules

Now i am able to start Splunkd from the command line IF I set the environment variables SPLUNK_HOME, SPLUNK_DB,PYTHONHOME . But if I start as a service it does not work (i.e. net start splunkd )

How do I set the enviroment variables ?

Regards Haro