My company will be upgrading our SharePoint 2007 site to SP2010 and I know how to do it. But there is one step in the migration step that I don't.
The pre-upgrade checker will give you a list of components/solutions that are referenced in the contentDBs but is not installed on the upgraded sharepoint farm.
What do you do if the component is not available for 2010? (I believe the only option is uninstall the component before migration). Even if an upgrade is available for upgraded components won't it have a different GUID and therefore not solve the migration error messages?
In other words, isn't it true that "install missing components" advice for 07 components only work if the 07 components works in 2010 (which I think is very few components.).