Not sure if this is a software or a hardware issue, so I will post to both forums. I recently bought Logitech keyboard+mouse combo MK700 after reinstalling Windows Vista Home Premium on my HP Pavillion a1600n desktop computer. (I have 1gb RAM + 200gb hard drive). The problem is that the mouse (MK620?) will not click on my Windows welcome screen, on the icons for the separate desktops that I utilize for myself, my wife, and kids. Once past this welcome screen, the mouse is fine. It just will not click here. However, I have had issues with the mouse not clicking at all. I just installed Setpoint 6.1 and those problems have not resurfaced, yet. Any suggestions on how to resolve this issue are greatly appreciated.