I have a USB HD, which doesn't have a power supply. it works from the laptop, but not the pc. PC troubleshooter says there's not enough power from the USB port, and to try an adapter. The lead for the drive has a third USB plug.
Can you get mains adapters which use the third plug to power the drive?

thanks

 

Plug the third connector into the host PC.

Mini usb in the drive, 2 x standard USB in the host = more juice for drive
Quite a common arrangment but more usual from laptops than desktops.

 

Amazon.co.uk: LINDY USB Cable - Dual Power, 2 x Type A to mini B, USB 2.0, 1m: Electronics & Photo

 

will try, cheers