I tried to ask this a question, but it would not submit. If it happens to show up twice, I apologize. Let me give you a little background information first, and then I'll discuss the problem. We have(had) TFS 2005\WSS 2.0\SQL Server 2005 running on a Windows Server 2003 SP 2. We decided to upgrade to TFS 2010\SharePoint Server 2010. We talked with a Microsoft provided consultant who advised us that the success rate of upgrading WSS 2.0 to 2010 was not good. Since we did not have a lot of customization or documents on the WSS side, we went with a clean install on a couple of Hyper-V VMs and were able to successfully migrate our TFS database to TFS 2010. All the new stuff works great. In the meantime, I made a virtual image of our TFS 2005 server and used that vhd file to create a new virtual machine so that I could attempt an upgrade to WSS 3.0. I followed the steps in this kb article (http://support.microsoft.com/kb/952692). I ran the prescan tool and there were no errors returned. I then proceeded to do an in place upgrade. WSS 3.0 was successfully installed and I was prompted to run the configuration wizard, which I did. I followed all the steps. Everything appeard to complete and the Central Administration page was loaded to the "Upgrade Running" page. Even though it says it is setup on a timer, I was forced to refresh the page manually. The process ran for a couple of minutes and then gave me an error message referring me to the upgrade log. When I check the log, this is the first Error block. [AssemblyReferenceFixUp] [3.0.4.0] [DEBUG] [2/23/2011 11:42:26 AM]: Application Web Config for this IIS site (1) is found at c:\inetpub\wwwroot\web.config. [SPIisWebSiteWssSequence] [ERROR] [2/23/2011 11:42:26 AM]: Action 3.0.4.0 of Microsoft.SharePoint.Upgrade.SPIisWebSiteWssSequence failed. [SPIisWebSiteWssSequence] [ERROR] [2/23/2011 11:42:26 AM]: Object reference not set to an instance of an object. [SPIisWebSiteWssSequence] [ERROR] [2/23/2011 11:42:26 AM]: at Microsoft.SharePoint.Upgrade.AssemblyReferenceFixUp.EnsureCurrentSafeConrolEntry(XmlDocument webConfig) at Microsoft.SharePoint.Upgrade.AssemblyReferenceFixUp.Upgrade() at Microsoft.SharePoint.Upgrade.SPActionSequence.Upgrade() [AssemblyReferenceFixUp] [3.0.4.0] [DEBUG] [2/23/2011 11:42:26 AM]: Begin Rollback() [AssemblyReferenceFixUp] [3.0.4.0] [DEBUG] [2/23/2011 11:42:26 AM]: End Rollback() [AssemblyReferenceFixUp] [3.0.4.0] [DEBUG] [2/23/2011 11:42:26 AM]: Begin Dispose() [AssemblyReferenceFixUp] [3.0.4.0] [DEBUG] [2/23/2011 11:42:26 AM]: End Dispose() [AssemblyReferenceFixUp] [3.0.4.0] [DEBUG] [2/23/2011 11:42:26 AM]: Elapsed time: 00:00:00.0468735. [SPManager] [ERROR] [2/23/2011 11:42:26 AM]: Upgrade [Microsoft.SharePoint.Administration.SPIisWebSite] failed. [SPManager] [ERROR] [2/23/2011 11:42:26 AM]: Object reference not set to an instance of an object. [SPManager] [ERROR] [2/23/2011 11:42:26 AM]: at Microsoft.SharePoint.Upgrade.AssemblyReferenceFixUp.EnsureCurrentSafeConrolEntry(XmlDocument webConfig) at Microsoft.SharePoint.Upgrade.AssemblyReferenceFixUp.Upgrade() at Microsoft.SharePoint.Upgrade.SPActionSequence.Upgrade() I've tried a few things based on some of the forum replies I've seen to this problem: 1. I checked that the web.config file does exist at the location specified. 2. All appropriate permissions have been set on the web config. 3. I've re-run the upgrade using the PSConfig command line tool. No success, WSS 3 is there, but will not convert the existing sites. One other thing that I tried. There were virtual directories under the default web site (the one WSS 2 was using). I came across an article that said this wasn't supported in 3.0, so I removed the virtual directories before running the upgrade. I continued to get the same error message. Since I have it on a vhd, after each unsuccessful attempt, I restore the vhd file back to its "pristine" state. I'm hoping that since this product is so old, that somebody has seen and corrected this problem. Does anybody have any ideas on what might be going wrong?