You might want to try stopping any of the remaining CF services (such as the .NET service), then seeing if you can delete the ColdFusion10 base folder. If that doesn't work, then try setting those services to "disabled" and rebooting the server, then see if you can delete the ColdFusion10 folder. it sounds like one of those services is still running, and has the folder open. Once you get that done, try going back to the add/remove programs and see if you can uninstall the .NET CF service - it should give you an error saying that it cannot find the uninstall folders, and do you want to just delete it from the list.
When you reinstall CF10, it might still see some params from the previous install, that are defined in registry keys, but I haven't seen those to cause any problems in the past.
-reed