Adding system memory ( RAM) is often the best way to improve a PC's
performance, since more memory means more applications are ready to run
without accessing the hard drive. However, upgrading memory can be
difficult and costly, and some machines have limited memory expansion
capabilities, making it impossible to add RAM.

ReadyBoost is a disk caching technology first included with Microsoft's
Windows Vista operating system. It aims to make computers running
Windows Vista more responsive by using flash memory on a USB 2.0 drive,
SD card, CompactFlash, or other form of flash memory, in order to boost
system performance.
ReadyBoost uses the flash drive to store
information that is being used by the memory manager. If you are
running a lot of applications on a system that has limited memory,
Windows ReadyBoost will use the flash drive to create a copy of virtual
memory that is not quite as fast as RAM, but a whole lot faster than
going to the hard disk. What is very cool here is that there is nothing
stored on this flash disk that isn’t also on the hard disk, so if you
remove the flash drive, the memory manager sees the change and
automatically goes to the hard disk. While the performance gain from
ReadyBoost is gone, you don’t lose any data and there is no
interruption.
Here are the requirements for a ReadyBoost-compatible USB Device:
- The USB Key must be at least USB 2.0
- The
device must be able to do 3.5 MB/s for 4 KB random reads uniformly
across the entire device and 2.5 MB/s for 512 KB random writes uniformly
across the device.
- The USB Key has to have at least 64mb of free space
Windows ReadyBoost relies on the intelligent memory management of
Windows SuperFetch
and can significantly improve system responsiveness.Windows SuperFetch
enables programs and files to load much faster than they would on
Windows XP–based PCs.
SuperFetch monitors which
applications you use the most and preloads these into your system
memory so they'll be ready when you need them. Windows Vista also runs
background programs, like disk defragmenting and Windows Defender, at
low priority so that they can do their job but your work always comes
first.
NOTE: Superfetch is enabled by default. 1. Open the Start Menu.
2. In the white line (Start Search) area, type
services and press
Enter.
3. Click
Continue button for UAC prompt.
4. Scroll down and right click on
Superfetch and click
Properties.
A. To Disable Superfetch - 1) Click the
Stop button and click
Disabled under the Startup type: drop down menu.
2) Click
OK.
B. To Enable Superfetch - 1) Click
Automatic (Under Startup type) and click the
Apply button, then click the
Start button.
2) Click
OK.
3) Close Services window