Ignore the message and install win 7 or uninstall those and reinstall the windows 7 versions if available after the upgrade if you miss them. If I were you, I'd skip all of them. You don't need them. Datasafe is a trial backup program that you have to pay for. When your dell datasafe subscription runs out, your backups are gone. Keep your backups on an external hard drive that you control. You won't need the dock or the modem diagnostic with Win 7.

I religiously followed every suggested uninstall-before-upgrade and found only one problem (with my XPS M1530): the Sigma Tel driver; see my post "Upgrading Vista to Windows 7 ..." just after yours. Let me know how it goes, especially if you have a Sigma Tel CODEC on your motherboard.