How to install windows xp

Hello,
I dont know what exactly has happened to Toshiba Satellite laptop, its MODEL NO. = PSL2XL SERIES = 01R007
. I installed four to five softwares in laptop and from that time laptop was slow down and suddenly hanged. Now it has left only two options that it only starts and shut down. So please please help me what shall i do ? AND I AM WORRIED COS IT WAS NOT MY LAPTOP IT WAS MY FRIENDS LAPTOP SO PLS HELP ME.....