I upgraded from XP to Windows & Office 7. The WD external hard drives worked quickly without delay time with XP. Since updating to 7, the drives are extremely slow when opening, saving, doing anything on the hard drive. What is the difference and why the major change? Lost, confused & wasting time.
Try running a diagnostics using WD DLG to make sure there is nothing wrong with your drive.
Also make sure the drive is plugged in directly into a wall outlet. Avoid any extension cords, power strips and surge protectors.