Imagine you had to make a script that could run for hours.

http://www.aspnetemail.com/samples/webmailer/

Wrapping your mind around this script will change your perspective ....
Read that script really closely. What is does is so far beyond what first
glance would indicate.

The script initiates a thread that can run independently for many many
hours after the few seconds the script runs.

In fact the only reason that script refreshes itself is to monitor the
threads progress
=> not to sustain it <=

so if developing deploying or Admin Access to create a service is not
possible, long running tasks can be done anyway without services.