A primeira coisa que acho é eliminar o Windows XP, já está obsoleto .
Como é um computador antigo, acredito que não seja viável instalar um sistema como o Windows Vista, ele requer um hardware melhor para ser executado corretamente.
Eu aconselho você a instalar qualquer distribuição Linux, como o UberMix
.
The ubermix is an all-free, specially built, Linux-based operating system designed from the ground up with the needs of education in mind. Built by educators with an eye towards student and teacher empowerment, ubermix takes all the complexity out of student devices by making them as reliable and easy-to-use as a cell phone, without sacrificing the power and capabilities of a full operating system. With a turn-key, 5 minute installation, 20 second quick recovery mechanism, and more than 60 free applications pre-installed, ubermix turns whatever hardware you have into a powerful device for learning.