Not critical to the installation, but will allow it to activate without any phone calls. If you want to keep some of the bundled stuff, I'd try just uninstalling the bits you don't need. You could use autoruns and process explorer from sysinternals to see what is running, and reduce the load that way. Alternatively, you might find the HP support site allows you to download the software individually, and you could add the bits you need on to a clean install.