Harddisk problems

Q, Hey dude my pc has recently become unreliable,Taking an age to boot up at sometimes or not starting at others.I've tried booting from the windows Cd and the system starts on,So it might be the hard disk that might be wrong?

A,Yeah,you might be wright mostly harddisks are the components which dont last forever depending on there usage and there environment some could last less than five years the basic symptons for disk failures are such as slow start-up's or the inability to boot on some occasions. Sometimes the Bios also gives away the game starting it cannot find an operating system or is unable to boot from the disk.Most of the disks sont fail overnight there by gining an opportunity to copy data off the disk.Even disks that appear to have failed are worth a rechecking either way it's time for new one.