Removing IMVv1 prior to installing E2K3 SP2
There was a discussion today on one of the mailing lists I am on about the IMFv1 and the fact that it does not always remove properly. Prior to installing Exchange 2003 Service Pack 2, you should always make sure you logon as the account that installed the original version of the Intelligent Message Filter, go in to Control Panel -> Add/Remove Programs and remove it. If you can't get it to remove (or even find it in Add/Remove programs) re-install it from the original program and THEN remove it.
The discussion came about because Microsoft has removed the IMFv1 installation MSI from their web site. If you need it, send me an e-mail offline. See Bharat Suneja's blog for more info on the removal of the IMVv1 from Microsoft's site.
Anyway, the fruits of this discussion came in the form of two useful links. One from Evan Dodd's blog where he covers what the prereq check is actually looking for. If IMFv1 is installed, then at HKLM\Software\Microsoft\Exchange for a value called “ContentFilterVersion”. This value should be GONE if you are installing E2K3 SP2. See Evan's blog "IMFv1 getting in the way of your SP2 upgrade?" for more information.