While reading xp format cd my laptop shutdown

Hello,
Please help me guys. I have HP 530 laptop. I put on my laptop windows 7 and then i didnt like how it works (i think the laptop configuration is not good for win7). I wanted to format it with XP format cd. I put the cd and i make it to read. while blue screen (reading the format cd) "WINDOWS SETUP" it is reading the files normaly and then my laptop turns off. I realy dont know how to format it. Also i have another problem. I cant acess my laptop cause i dont know how but BOOTMRG is missing from windows 7.. And i dont have the windows 7 now beacuse i did it from USB.. Any answers... Thanks from now.