Modifying and disabling Prefetch settings As with most Windows XP-related things, you can change the way that Prefetch behaves by making a change in the registry. For low-memory systems, you can even completely disable the feature, which ensures that every last byte of RAM goes toward running current programs, not the ones XP guesses you'll need next. To change the registry settings for prefetching, start the Registry Editor by selecting Run from the Start menu, typing regedit in the Open text box, and clicking OK. When the Registry Editor window opens, navigate through the left pane until you get to this hive: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters In the right pane, look for the key named EnablePrefetcher. The value of this key represents how prefetch works on your system. Values you can choose from include: 0—Disable 1—Application Launch Prefetch 2—Boot Prefetch 3—Prefetch everything To change the value, double-click it. You'll then see the Edit DWORD Value screen. Enter the value representing the level of prefetching you want in the Value Data field. As a general rule, if you're on a low-memory workstation, 128 MB or so, set the value to 0. If your workstation has 512 MB of RAM or more, set it to 3. Otherwise, you can choose the value as best suits your needs and observations.