hi, i'm new and i think i have a serious problem with my XP....

my sister defrag our computer last week because when she was going to use powerpoint the error message "only part of writeprocessmemory or readprocess memory of requested file was completed" appears, actually we cant use any program from the computer and that message always appears whenever we click on something....nothing and i mean nothing works...even the internet explorer....some of my sister's friends said it's hopeless....they said the motherboards is screwed up....but i need a secoond opinion. please help...

no one??? ok....