Every loves the ERP system, its the life blood of the organization. Several years ago and what seems like a galaxy far far away when I lived in Las Vegas, I decided to let the pro's upgrade and i was going to be a spectator. The real issue wasn't the ERP system or the pro's, it was a PEBCAK. after 3 days of down time following the worst ERP that could be there was nothing. No access, DB was upgraded so with out restoring a huge amount of data there was no going back, so the issues was diagnosed to be the process server.
This was a three tier setup so we had the SQL server, Process server and clients. the Process server was just upgraded to 2003 SP1, who remembers that fun time? Well I do. That was when Microsoft decided the W3WP internet worker process was bad. Not only did i spend hours and probably too many time uttering some profane terms, but i had to find out from South Africa support that i had to make an exception since the release of SP1 in order to allow that process to run correctly.
Once the exception was make, life came back to normal, this wasn't before, three repeated rebuilds of the server and several international phone calls. everything was fixed, I and my team were hero's again, but the lesson learned from that, had me uttering the words for years, every time there was a issue with a Windows server, "Thanks Bill" !!!!!!!!!!!!!!!!