SP4 includes the following fixes:
When you install SP4:
1. If USB 2.0 support is already configured, your current USB 2.0 drivers will be updated.
2. If USB 2.0 support is not yet configured, you must manually install the new drivers:
A. Right-click My Computer and press Manage.
B. Expand System Tools and double-click Device Manager.
C. Use the View menu to select Devices by type.
D. In the right-hand pane, find the USB 2.0 Enhanced Host Controller Interface (EHCI) Host controller, either under Universal Serial Bus controllers or Other Devices as Universal Serial Bus controller with a yellow exclamation mark (!), right-click it, and press Properties.
E: On the Driver tab, press Update Driver.
F: Press Next.
G. On the Install Hardware Device Drivers page, press Search for a suitable driver for my device (recommended).
H. Press Next.
I. On the Locate Driver Files page, under Optional search locations, clear any of the following check boxes if they are selected:
Floppy disk drives
Specify a location
Microsoft Windows update
J. Press Next.
K. Press Next to install the recommended driver.
L. Press Finish.