I ran the stsadm -o preupgradecheck and I get this issue reported but I can’t see any reason there is actually a problem.
The following web part(s) are referenced by the content, but they are not installed on the web server
Id = fba9904f-0876-1305-2239-8087396edddd, Type = Unknown, Reference = 68, Status = Missing
Id = b6a15317-c519-a4ff-4ae7-8ce93db381dd, Type = Unknown, Reference = 17, Status = Missing
Id = 633dab9d-ddde-d40c-534b-b711f9df8bcd, Type = Unknown, Reference = 92, Status = Missing
I used both stsadm -o enumallwebs and a SQL query to identify the pages where these webparts are being used as described here
Preparing the SharePoint 2007/WSS3 Database for Upgrade
I then used used Easy SharePoint WebPart Type ID Generator to correlate web part IDs to the web part types
When I goto the pages where the web parts are being used I can see the web parts on the page and they work fine. When I add ?contents=1 to the URL to get to the Web Part Maintenance Page I don’t see any error web parts. I can also see the web parts in the Web Part Gallery of the site collection.
These are custom web parts that were deployed by a feature that is a part of a SharePoint solution. The SharePoint solution is added to the farm and deployed to the Web Application. The Feature is actived in the Site Collection. When I look under the 12 hive I can see the feature and all the necessary files.
What am I missing? Is this really an issue? Will this issue prevent the upgrade to SharePoint 2010
TO address your questions
try removing the webparts from page and re run the pre upgrade check and see if you still get the error. if yes the problem is some where else check your 12 hive logs
I don’t think this is a big issue to prevent your upgrade as always in upgrade or at time of restoration wsp deployment is last step even if it says some weparts are not installed it should not affect you upgrade process