LOL

For the sister who probably will have WWIII wiht her brother if she doesn't fix it,

Start>>>Programs>>>Accesories>>>System tools>>>System restore (if you are running on windows XP)

Just restore to an earlier time when the files were still present on your computer...about 2 or 3 days back....(depending on how many saved restore poinst you have)

Inshallah that should undo the damage done...