Write-behind caching returns control of the system to you while the hard disk is still writing data, enabling you to perform other tasks without waiting for the last data-write process to complete. By default, Windows disables write-behind caching on external hard disks connected to hot-swap ports such as USB or FireWire. The reason? You can disconnect the hard disk from these ports at any time, and Mama Microsoft doesn’t want you to lose any data. However, if you’re already accustomed to using the Safely Remove Hardware control in the taskbar to disconnect your USB or FireWire hard disk, you should enable write-behind caching.

To enable write-behind caching on an external hot-swap hard disk:

1. Open Device Manager (it’s available from the Tasks pane of the System properties sheet).
2. Expand the Disk Drives category.
3. Select your external disk drive (a USB drive will have "USB" as part of the device name).
4. Click the Policies tab (Figure 5).
   

   Figure 5 Select Optimize for Performance to improve the performance of an external USB or FireWire (IEEE-1394) hard disk.

5. Click Optimize for Performance (Figure 5).
6. Click OK.
7. You must restart your computer after selecting this option before it becomes active. Click Yes to restart your computer now, or No if you will restart your computer later.