I want to migrate one of my Site Collections from SP 2007 to SP 2010. I just realised that there are quite a few custom solutions installed on my 2007 farm that have been deployed globally to all site collections, even though not all of them require it. As a result I have solutions in the Site Collection I want to move that I don't really need. So instead of updating the solutions from 2007 to 2010 and installing them on the 2010 farm, I simply want to delete the 2007 solutions out of my Site Collection first, then migrate the site collection to 2010. Sounds simple, I thought. However, there seem to be problems in this: I have removed most of the custom solutions from my 2007 site collection, yet they still show up in the log as missing features when I run test-spcontentdatabase. Is there something else I have to do other than retract the solutions from the site collection that I want to move? Or do I really have to remove the entire solution off the farm? I don't want to do that because I am only migrating a single Site Collection at this point. All other site collections still need the features that are installed on the SP 2007 farm. Thanks for the feedback.

You do have to remove then with a retract from central admin and a removal using stsadm stsadm -o deletesolution solution nameKris Wagner, MVP, MCITP, MCTS Twitter @sharepointkris Blog: http://www.sharepointkris.com/blog

So that means I have to remove the solutions from all Site Collections even though I only want to upgrade one of them to SharePoint 2010? Is there any workaround for this? Thanks