encotrei esta página com uma miríade infindável de informações úteis sobre o XP.
A título de exemplo, e que contraria directamente o que a malta cá no fórum costuma dizer, passo a citar, lol:
Disabling System Restore
Myth - "Disabling System Restore improves performance."
Reality - "System Restore does not cause any noticeable performance impact when monitoring your computer. The creation of a Restore point also is a very fast process and usually takes only a few seconds. Scheduled System Checkpoints (every 24 hours by default) are created only at system idle time to avoid interfering with a computer during use." - Source
Large System Cache Tweak
[HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\MemoryManagement] "LargeSystemCache"
Myth - "Enabling this improves desktop/workstation performance."
Reality - "LargeSystemCache determines whether the system maintains a standard size or a large size file system cache, and influences how often the system writes changed pages to disk. Increasing the size of the file system cache generally improves file server performance, but it reduces the physical memory space available to applications and services. Similarly, writing system data less frequently minimizes use of the disk subsystem, but the changed pages occupy memory that might otherwise be used by applications. On workstations this increases paging and causes longer delays whenever you start a new app. Simply put enable this on a file server and disable it on everything else." - Source
"System cache mode is designed for use with Windows server products that act as servers. System cache mode is also designed for limited use with Windows XP, when you use Windows XP as a file server. This mode is not designed for everyday desktop use. When you enable System cache mode on a computer that uses Unified Memory Architecture (UMA)-based video hardware or an Accelerated Graphics Port (AGP), you may experience a severe and random decrease in performance. For example, this decrease in performance can include very slow system performance, stop errors, an inability to start the computer, devices or applications that do not load, and system instability." - Source
etc, etc...
xp secrets, myths, etc.. em http://mywebpages.comcast.net/SupportCD/XPMyths.html
Abraço





