Well it's over. Our PC's are all now on Eastern Standard Time and our users didn't have to do anything to their PC's or calendars ... a huge success in my book.
We did have 1 user that the calendar script would not fix ... for whatever reason the script would not run against her mailbox. 1 out of 135 mailboxes ... not bad at all!
We did end up manually updating the time zone on each PC via remote desktop and DameWare. We used a time zone change script and ran it in a user logon script (we never got a machine logon script to work correctly) ... so all we had to do was log on then back off each PC. Took 3 of us about a hour to hit all the boxes (thanks for the help Dustin!). It was also a good time to prune Active Directory of domain machines that no longer exist. I pulled away from the church at 2:12am ... we could have went home much earlier, but we all felt pretty peppy and pushed on.
I learned that Domain Controllers don't like it when you change their time zone. We had a moment of panic when both DC's stopped replicating after zone change. Reboot them both and their happy again.
We also discovered more C: drives nearly full ... when a P4 2.8GHz box with 1GB ram takes a while to boot up you know something's wrong. Disk quotas are on the horizon.
The last 2 weeks have been overwhelming. I'm just so glad to have this time zone crap behind us.