Windows XP gives you a possibility to increase PC performance by removing some visual effects. After having removed visual effects you`ll get additional free space of RAM memory, increasing the speed of Windows XP loading, some increasing of the executing speed of the processes but you will lose XP visual effects. That is your decision. To change the configuration of visual effects you must open Performance Options page. For that:
Press Windows + Pause/Break buttons of your keyboard. Click on Advanced System Settings tab.
Press Settings button of Advanced tab of Performance section.
Select a suitable configuration for you: for the best appearance or for the best performance and press Apply button.