My external hard-drive keeps unplugging itself… Urgently need to fix this issue?

I think it could be a USB energy issue since the ports don’t sound like giving that 500 mA desired.I have no clue how to correct this.
My additional hard-drive is additionally connected on the mains hence I do not understand.I’m applying windows Vista.

The commute works for a couple of mins in that case it unplugs per se and WE often have a pop-up message telling me to use a faster 2.0 usb relationship but MY PARTNER AND I thought my ports ended up 2.0.Please help!

even though you have a power supply you would like a USB cable tv with 2 USB connectors to ensure enough strength for spin and rewrite up plus maintain your file program.