One of the biggest complaints about upgrading to a new Windows version is that the new system doesn't perform as speedily as its predecessor on the same hardware. This isn't actually the case with Windows 7, which performs much better than Vista on the same hardware. But it could be an issue if you've upgraded from Windows XP. And regardless of the performance attributes of your PC, faster is always better.

There are many ways to improve the performance of a PC running Windows 7. But if you're using a PC with 2GB or less of RAM, and have a PC that is hard or impossible to upgrade further, like a netbook, one excellent option is a Windows 7 feature called ReadyBoost. This technology uses spare storage space on USB-based memory devices such as memory sticks to increase your computer's performance. It does this by caching most-frequently accessed information to the USB device, which is typically much faster than reading directly from the hard drive. (Information cached to the device is encrypted so it can't be read on other systems.)

There are a number of caveats, of course. First, the USB device you choose to use must meet certain speed characteristics or Windows will not allow it to be used in this fashion. Second, storage space that is set aside on a USB device for ReadyBoost cannot be used for other purposes until you reformat the device.

Secret: In previous versions of Windows, you were limited to the use of only one USB device and a maximum ReadyBoost cache size of 4GB. Both of these limitations have been lifted in Windows 7. So, if necessary, you can use multiple USB storage devices for ReadyBoost, and you can use more than 4GB of space on each. Such a scenario is, however, unlikely.

ReadyBoost has the most impact on systems with less than 1GB of RAM, and it clearly benefits netbooks and notebooks more than desktops, as it's often difficult or impossible to increase the RAM on older portable machines.

When you insert a compatible USB device into a Windows 7 machine, you will see a Speed Up My System option at the bottom of the Auto Play dialog that appears, as shown below.

Windows 7 Feature Focus: ReadyBoost
USB devices advertise that they can be used for ReadyBoost.

When you select this option, the ReadyBoost tab of the Properties dialog of the associated device will appear, enabling you to configure a portion of the device's storage space. It recommends the ideal amount based on the capacity of the device and your system's RAM (ensuring a minimum of 1:1 and maximum of 2.5:1 ratios of RAM to cache).

Windows 7 Feature Focus: ReadyBoost
ReadyBoost provides an inexpensive and simple way to boost performance on low-RAM PCs.

Obviously, ReadyBoost won't work unless the USB memory key is plugged into your PC. This can be a bit of a hassle because you need to remember to keep plugging it in every time you break out your portable computer. Still, ReadyBoost is a great enhancement and a welcome feature, especially when a PC would otherwise run poorly with Windows 7.

Tip: If you have an SD card slot in your notebook or netbook computer, I recommend using an SD card for ReadyBoost instead of a USB memory stick. That's because you can leave the SD card plugged in all the time, and you won't lose it or forget to plug it in when you need to use your computer. This is what I do with my own netbook computer, and it makes a difference.

Windows 7 Feature Focus: ReadyBoost
SD card slots, like this one in a netbook PC, are ideal for ReadyBoost.

Secret: If you're using a PC containing a Solid State Drive (SSD) ? a drive similar to a flash stick vice a spindle of spinning platters ? ReadyBoost will be disabled, because the disk is fast enough that ReadyBoost will unlikely provide any additional gain in performance.

Portions of this article appeared in edited form in Windows 7 Secrets. --Paul