3 hours? Ouch. Even on a lower end PC like that without much memory, it shouldn't take more than 15-20 minutes. Tops.
The USB 3.0 recommendations are good, fellas. But that sounds like an older PC, and he probably doesn't have a 3.0 port on his board. You need the 3.0 access port + 3.0 hardware + 3.0 cable to take advantage of the additional speed offered. If one component is missing, might as well fuggetaboudit. Make sure your PC's USB port is 3.0 compatible, it will have the 3.0 logo next to it.
1) Check your USB cable for frays and/or breaks and pinch points. The wires inside may be broken. Also check and clean the actual plug ends. USB cables are cheap as dirt, so replacing it should be your first point of eliminating the problem.
2) Check your USB ports. Having you tried using other USB ports, or are you using the same one? Ports can get dirty, or one of the pins may be worn and/or broken.
3) Run WinStat. It's a command prompt tool that can give you an overview on USB performance. Do a Google search for how to do this, I won't go into the nitty-gritty details here.
4) Device Manager > Hard Disk > Disk Drives > Find your USB section and select the "Better performance" option. This allows write-caching.
5) Sometimes those eco-friendly power settings can effect transfer speeds. Power Settings > Advanced Settings. Make sure you're running "high performance" in your power management plan.
There are some other more complicated options through bus and BIOS, but I highly suspect that if you do 1-5 above, your problem will be solved. If not, it's probably an issue with your motherboard.
Good luck!
