Hi Ubuntu forum for beginners,

I installed ubuntu 12.10 on my pc as a dual bootable with windows XP. I startet with installing windows XP and with that errasing all the old data that lied on the harddisk. Afterwards I downloaded Ubuntu from the internet, and everyting went smooth
Now windows XP works quite fast, but ubuntu is very slow.
What could be the problem?

My pc: desktop, fujitsu-siemens, 7 years old, intell pentium 4 cpu, 2,6 ghz, 1,5 gb ram, radeon 9200 sec