windows XP booting

my windows XP system got a virus in the “pagefile.sys” file,and about then my avast antivirus subscription expired,-so now my windows XP won’t boot properly(it boots and restarts,then stays in that looped state of booting and shutting down.Anyone has a solution,please help me out-I had just started a graphics design project,and I’d love to see it through-Thanx already!