Lets face it ! Tweaking gives us the satisfaction...of having done something to beat the system ! There is that urge, esp amongst die-hard tweakers, to squeeze out the last drop of performance ! Frankly speaking, the best "tweak" is to throw RAM at it ! Its one BIG healthy dose of tonic to perk up your machine.

There are some tweaks which can at best be considered to be of dubious value. Though most of them may not cause much harm, some of them, if applied indiscriminately may actually hurt performance. Some of them worked with older Windows versions, but are redundant & irrelevant now.

Always Unload DLL (Disable DLL Caching) to free up memory and improve performance. Using this tweak on Windows 2000, XP or Vista has absolutely no effect. This registry key is no longer supported in all post-2000 Windows OS's.

Cleaning the Prefetch Folder. Every time you clean up the Prefetch folder, you delay application load times, the next time you launch them. Its only after the second time that you regain optimal application load times. Only one Prefetch file is created per application . Windows cleans this folder at 128 entries, and the old ones automatically get deleted after a few weeks. In Vista this folder does not occupy mre than around 50MB. Cleaning the Prefetcher can therefore be construed actually as a...a temporary self-inflicted unoptimization ! Now why would you want to do that ! The developers of the memory management system of Windows Vista have done a good job...no question about this one.

Disabling Certain Services. Dont take this advice to its extremes, for in fact this could actaully cripple your system ! For instance Disabling the task Schedular to improve performance actuall prevents the Prefetcher and the Layout.ini file from forming or being updated ! Forcing, inter alia, longer application startup times. Never ever shutdown the System Restore Service...never know when it may save your day ! Disbaling the DNS Client Service may decrease the the overall performance of the client computer, and the network traffic for DNS queries increases if the DNS resolver cache is deactivated. This effectively reduces Internet Performance for sites you have previously visited and puts an unnecessary load on your ISP's DNS server.

So do refer a good Services Guide like BlackVipers. Or simply use a safe Program like Tune-Up Utilities. Shutting down services indisciminately is a sureshot prescription for trouble !

Page (Swap) File Tweaks. "Create a Fixed Size Page File to improve performance" : This was relevant in the earlier days of Windows; Definately irrelevant for Vista ! "Eliminate your Page File completely, if you have a large amount of memory installed" : There are simply NO published benchmarks establishing any performance gains from doing so ! And in any case Windows wasn’t designed to run without a page file.