Help me please my computer is in really bad shape?

Ok please people on yahoo answer help me my pc is really doing bad it turns its self off losing its internet and just is really slow and it bad shape i have an anti virus norton 2007 but whenever i run a scan the computer turns its self off and when i run a styam restore it says there are no dates to restore please help me i am really at my wits end and i talk to my mate and everything using windows live messenger and i will have no way of contecting them as i am disabled and when walking and running get tired within half an hour so please help me fix this any body who can help me futher plz do so

I also used to have Limwire but got rid of it

Thank you for reading this all

Help me please my computer is in really bad shape?downloads

is ur computer old?

i need some kind of computer engineer!!!

i am not a computer expert!

i think its probably cuz u had limewire!!!

u need an expert!!!