One of the most efficient ways to improve the speed and performance of your computer system is to add random-access memory (RAM). Replacing RAM modules requires physically opening your computer case and removing parts, which is a daunting prospect for most computer users. If you have a flash memory device, such as an 8-gigabyte (GB) SD card, a feature of the Windows Vista operating system allows you to use the card as RAM instead of physically adding new RAM modules.
Examine the ports on the front and back end of your computer to see if the machine has a built-in card-reading unit. Get an external card reader if there is not a built-in unit and connect it to one of the open USB ports on the machine.
Insert the 8GB SD flash memory card into the corresponding SD slot on the internal or external card-reading unit. Wait for the Windows Vista operating system to bring up a new window asking what action you want to take.
Scroll down to the bottom end of the window and find the heading labeled "General Options." Click on the link underneath the "General Options" heading that is labeled "Speed Up My System Using Windows ReadyBoost."
Click on the radio button at the top of the ReadyBoost window that is labeled "Use This Device." Click on the slider bar at the center of the window that is labeled "Space to Reserve For System Speed."
Drag the slider and choose the amount of space on the SD card that you want to use as system RAM. Put the slider all the way over to the right side to use all the available space as RAM. Click on "Apply" and then close the window.
Return to the ReadyBoost menu if you want to turn the feature off. Click on "Do Not Use This Device" and then click on "Apply."