Hi all I might (very big might) have found out a foolproof way of installing ISA, (it also may only be foolproof on my network, no promises.). 1.Install Win2k 2. Install all the windows update files from the Windows update site. 3. Install SP1 4. Install ISA 5. Install SP2. Ive done this 4 times over the last 3 days on 4 different servers and all of them have worked flawlessly (including the mail screener) without rebooting. Steve Moffat