How can I use Group Policy in WinServer 2003 to prevent users' Acrobat Reader from checking for updates?

1. First, you need to find what registry setting it takes to make the change you want, then . . .
2. Deliver that setting to your clients.

For #2, however, you can create an ADM template,
or the information on a free download here at my web site: http://www.gpanswers.com/solutions/?id=8

Hope that helps...