Speed up your PC's performance Windows Vista features a new way to improve your PC's performance: Windows ReadyBoost. This feature lets you use flash memory on a universal serial bus (USB) 2.0 drive, Secure Digital (SD) Card, or Compact Flash to give you additional memory cache--memory that your PC can access more quickly than data on the hard drive. To take advantage of Windows ReadyBoost: 1. Insert a USB 2.0 memory drive with at least 512 MB of capacity. 2. When prompted, click "use this device to speed up my PC."