Windows XP partition problem

[NEM1S1S]

My problem is that I have an XP machine that trys to boot when it reaches the stage of when it should get to the desktop it just throws up a blue screen (which I don't get time to read) and reboots... normally I would just reinstall XP over the top, but when I boot off the XP CD I get to the partition section and it tells me that the existing partition is unknown.

Does anyone know what I can do to get the data back of of the HD?? It's a laptop btw.

The closest product I how come across that will do it is called ERD Commander 2003 but the problem is the price..... $4000... HUH!!!

Anything else that'll let you boot from CD and restore the partition without loosing files???

Thanks