ReadyBoost is a feature used with the Windows Vista and Windows 7 operating systems. With ReadyBoost enabled, a user can plug in a flash drive with at least 1 GB of space and use the space on the flash drive to help improve the performance and processing speeds of the computer. Depending on a user's setup, she may not notice the difference in speed, or the change is so nominal that it doesn't make a difference. Users can disable the ReadyBoost feature altogether to regain the space taken up on their flash drives.
Insert the USB drive that has the copy of ReadyBoost on it that you want to remove.
Click the "Start" button and then click the "Computer" or "My Computer" link.
Scroll to the "Device with removable storage" section and locate the USB drive that has ReadyBoost installed on it.
Right-click on the drive. From the resulting menu, select the "Properties" option.
Click the tab titled "ReadyBoost."
Click the option titled "Do not use this device." When you are finished, click "Apply," followed by "OK." ReadyBoost is deleted from the drive and the available space can now be used for extra storage.