I've noticed that people have had trouble setting up their handset with Vista. There's a very simple workaround for this with vista. Install the software provided, then locate the folder your software is located in. Typically this is: "Program Files > Logitech > Logitech Internet Handset" In that folder locate the file called LOGI_HDS.EXE Right click on this file and choose "properties" In the dialog that pops up click the "compatibility" tab at the very top. In this tab you'll see a section that says "compatibility mode". Check the box that says "run this program in compatibility mode for" and select "Windows XP (Service Pack 2)".
Then hit ok.
After that whenever you launch the program it should be able to initialize your handset.
Hope that works for everyone!
P.S. I think Logitech should offer me another handset for helping fix this problem for the peeved users on this forum