Sony vaio keyboard dongle - Power issues connecting to another computer
Assuming that your device is actually recognized by Windows as a HID-Keyboard and is overcurrent for the port.

The default HID drivers and the OEM extensions define the parameters (including current allowed). See here for a good starting description.

One way you might get around your problem is to use a 1 port Hub/extension cable or a non-powered Hub between your device and the computer. The Hub is by default 100 mA (or 500 mA in some cases) so the computer port is configured for that amount of current (check the error you get in Device Manager).

There are many cheap non-powered Hubs available, for example an active extension cable like this or a non-powered Hub like this.

The USB system is configured from the Root out, so with a Hub in the cable the computer port is configured to allow the current defined by its descriptors.