Failure id: MOCCHS-53G60T-XD7U2J-60RN03

i got hp pavillion dv4 entertainment dx series laptop with win7 core i3 .... I don't frequently use the laptop since I have another at work .... but before about two weeks I began to listen an unusual sound when I start up the laptop and during functioning ... even silly operations like opening a folder ... takes time saying not responding .... and regarding the start up and shutting down time ... forget it ... it takes about 15 minutes on both sessions..... and after days it will not proceed to window totally so I formatted it with win 7 .... and began to function smoothly except that after the format the first day ... blue screen came and memory dumped ... and started again ... but after that it was functioning cool but still with some 'not responding' headache .... finally again it could not proceed to windows .... when I checked it with ERD cd it will not still proceed and with diagnosis and bios information ... i came to find out that I got to change the primary hard disk drive .... ... Guys is it possible for Hard disk to crash like that or am I making mistakes in conclusion ..... thanx