i want to get rid of all my viruses,spywares,etc on my computer. And i dont want to purchase a program and pay. Does anyone know any free programs or does anyone know a link to a cracked version or something?

okay i have xp on my pc
but it is a cracked version and has a lot of viruses on it
so im gonna reinstall xp on my two pc's
back up all my data
but i want to buy an antivirus protection for my two pcs
i want to know whats the verrrrrrrrrrrrrrrry best out there
the best
i heard that kaspersky is the best
could you tell me which product is the best for protection.

thanks in advance