Determine USB Power Load

Determine USB Power Load: "Do your PC's USB ports supply enough electricity to power all the devices you have attached to them? Plugging too much gear into a bus-powered USB hub (one with no external power adapter) can overwhelm a USB port by demanding more than the 500 mA it can supply.

Check the power demands on any USB port in Windows XP by
right-clicking My Computer and choosing Properties,
Hardware,
Device Manager.
Double-click Universal Serial Bus controllers,
double-click the USB Root Hub entry,
choose the Power tab, and add up the amounts in the 'Power Required' column."

How to Prevent Users from Using USB Storage Devices

USB flash memory drives are handy, but they can also be used to upload malicious code to your computer or to copy confidential information from your computer and take it away. You can disable the use of USB storage devices. Here's how:

• In Windows Explorer, navigate to the systemroot folder (usually named WINDOWS) and then to the Inf folder.
  
• In the Inf folder, right click the file named Usbstor.pnf and select Properties.
  
• Click the Security tab.
  
• Find the name of the user you want to prevent from using USB storage devices in the list labeled Group Or User Names.
  
• In the Permissions list, check the Deny checkbox next to Full Control.
  
• Click OK.
  

Repeat the above steps for the file named Usbstor.inf.
Now the user(s) you selected will not be able to install USB storage devices to the computer.

If one is already installed, you'll need to edit the registry to prevent USB devices from working.

• In your registry editor, navigate to:
  HKEY LOCAL MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor
  
• In the right pane, double click the item labeled Start and in the Value Data field, enter 4 (make sure Hexadecimal is selected as the data type).
  
• Click OK and close the registry editor.