Dell 1907Fp monitor and windows 7

So, it looks like the USB connector is basically a connection to a USB hub that is built in to the monitor, and in no way conveys a signal to the monitor itself. There is a single upstream connection (between the computer and the monitor) and 4 downstream connectors to connect peripheral usb devices. Normally, you would not expect to find a problem connecting a usb hub unless a device were connected to the downstream connections that was screwing up Windows, or unless the BIOS or Windows was set to seek a boot device (some motherboards can be set to boot from a usb drive) or other critical device (keyboard?, mouse?) on USB and not finding it. Does your problem occur if no devices are connected to the hub? Have you checked your bios to see if booting from a usb device (external device) is enabled? If so disable it.

Is the same computer connected in both cases but using a different OS due to dual boot or other configuration or is it the case that the old computer worked but a new one does not, or did the old computer work under XP but the same computer fails to work under Win 7?