Why Is Tranferring Files From Windows 7 To My External Hdd Much Slower Than Using Windows Vista

Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7601) Service Pack 1

Processor: AMD FX(tm)-4100 Quad-Core Processor (4 CPUs), ~3.6GHz

Memory: 8192MB RAM Available OS Memory: 8174MB RAM

For some reason, transferring files of any size from the new machine to the external Acomdata HD is much much slower than previously using the laptops. What used to take 4 minutes to transfer files from the laptops to the external HDD now takes 35 minutes on this new desktop machine.

Why is the transfer rate so much slower using Windows 7 64-bit Ultimate on the desktop than it was on the laptops running Windows Vista and Windows X? All have been using the same USB connection so that’s not changed. Is there some sort of setting in Windows 7 that I need to tweak? Thank you.