PROBLEM OF BOOTING UP\r\nONCE I SWITCH MY PC IT

Most likely a hardware problem: either the memory is bad or the hard disk is no longer accessible. 
Go into the BIOS and put the cd first in the boot order. Then download and burn to a disk a Linux Live-CD like PCLinuxOS  http://pclinuxos.com/
Boot from it and in the boot options select Memtest - let it run for a while, it will tell you if it's good or not. If it is then let it boot fully and open My Computer - if it's there  and you can open it then it's either just a localized hardware fault (you will still have to replace it tho) or Windows was corrupted.
Use PCLinuxOS to recover all your files and reinstall Windows (this time use a much better antivirus like Avast). If after a short time you have the same problem then the hard disk is dying, replace it.