Two days ago I completed the upgrade of newagestore.com from Kentico 3.1a to 4.0.  This took roughly 4 hours to do, the process I took was a little laborious but perhaps the safest.

Backups and double checking backups all round
I took a backup of the database and then restored it into a new database
I took a complete copy of the site on the file system of the server and pointed it at my new database in the web.config
Created a new site in IIS to point to this new folder with a …