i have Acer laptopn extensa 4420 using win XP SP2. the problem is i install malware antimalware and scanned for virus found 3 virus then it says for restart. when i click OK to restart it taking time to shutdown. then i unplugged the power cable to turn it off because i dont have battery. after put the power cable back on and then try to boot the laptop its not booting. when i push power button the light comes up but it off quickly..i waited for almost 20 min then i tried again it works...laptop booted up and work fine.