I just installed exchange server 2007 service pack 3 and i'm finding out i may need to install update rollup 1 to solve an issue with vss backup. Had some issues installing service pack 3(hung for very long time on installing performance counters on hub transport role. eventually had to stop installation and start over). Is update rollup 1 a minor upgrade compared to sp3. How long should this take. will it require a restart of server.

Yes, required a reboot of server. Along with this, I would suggest you to install RU3 Version2 which also have prior RU update. We also had same issue with VSS after SP3 and fix by RU3 V3 installation. On base of my experience, i would suggest you to take a reboot of server before install RU1 or RU3 V2. Remove check mark from "Publisher Certification revocation" internet explorer-advanced settings. See below article for more detail , about how to install RU : http://exchangeshare.wordpress.com/2009/05/30/exchange-update-rollup-installation-it-is-not-nightmare/ Anil

I had problems with RU3-v2 ... hidden attachments on emails from Mac/Apple users ... I had to uninstall it.