How do i remove a proogram from my computer if the uninstaller EXE is broken Antivirus Xp 2008?

idk where it carme from but this program AnitvirusXp 2008 got on my computer and is messin stuff up it constantly reminds of virsus info that isnt true and it brings up thse warnings when i try to go to a page like yahoo saying that its dangerous and ask me if i want to procceed unprotected and i say no it just brings me to the sight where i have o register i want this SXXX off my computer cuz its makin it restart itself and all kinda messbut then i tried to uninstall it it says uninstall exe is broken and then i cant remove it from add remove programs how do i get it off?