Problems executing external application (.exe) using Windows service

i am gaurav from bangalore

i have one problem ,can u please help me out.

i have one windows application and one windows service.

from windows application i have to call one process "gpg" to encrypt my text file so i use

system.Diagnostics.process class to make new process.

my code is like this

Process processEncryption = new Process();

processEncryption.StartInfo.WorkingDirectory = @"c:\Gnu\GNUPg";

processEncryption.StartInfo.FileName = "gpg";

processEncryption.StartInfo.Arguments = @" -o " + "\"" + path + fileName + "\"" + " --passphrase " + passphrase + " -d " + "\"" + path + fileName + ".gpg" + "\"";

processEncryption.Start();

processEncryption.WaitForExit();

this code work fine if i use this code in windows application

but it does not work at all in windows service .code runs comepletely but does not produce any output "

it seems that this code is not able to start process "gpg" if we run in windows service.

can u help me

thanx in advance

bye