kubuntu slower than win xp (dimension 2400)

[Jon Redbeard]

Hello, I fix windows for a living but am new to linux. After playing with kubuntu for a couple days I'm really liking it and once I know how to use it better I will most likely switch to it full time at home. The main problem I'm having so far is that kubuntu runs VERY slow on my friends Dimension 2400, even slower than xp did previously. If xp had run slowly on this machine as well I would assume it was due to the speed of the hardware, but win xp ran everything at decent speed and pretty responsive in general. As I write this I'm trying to install Mandriva for dual-booting to see if it runs any faster. Any help would be greatly appreciated and if this has been solved elsewhere on the forum I'm sorry but I couldn't find it.

Celeron 2.4ghz processor
256mb ram
intel 845gv onboard video