I know this is a very old post and just wanted to add some information so that can help someone else facing the same issue
"The following virtual machines may be in use by another View environment." is a warning rather than blocking error, you should be able to ignore it and continue. If you can't, you can clear the existing View configuration information from the VM by editing the .vmx file and removing the machine.id configuration line. The registry data you see in the VM is being automatically populated based on that field.