I just bought a new computer (HP 4200+ AMD Athlon 64 bit x2 dual core Processor / 1 gig of ram/ 320 GB hard drive). I downloaded Avast 4.7 on it successfully, so I tryed a boot scan and after 30 mins or so the computer goes into sleep mode and never comes out no matter how long I let it run. Each time I have to cut the power to it to get it back running. I even disabled the Nortons anti-virus that comes on the computer. Could someone please tell me what I'm doing wrong.