Windows 7: printing not working in windows 2003 server from windows service

Hi,
I have created a windows service for printing PDF's through Adobe reader.
The code is as below.

Process.Start(exe,arg);

The command which executes from the above will be like below



C:\Program Files\Adobe\Reader 9.0\Reader\AcroRd32.exe,/h /t "D:\test.pdf" "\\servername\PrinterName" "" ""

This was working fine in windows 2000 server.
Now we are upgrading to windows 2003 server. In this it is not giving print.
Also I'm not getting any exception or any logs. Logs were created as everything working fine.
Also in 2003 server this is working from command prompt and
from console application also it is working, but when user logged in.
If no one is logged in again the print is not working.

Can please some one help me on this.

Regards
Madhu