Bad HDD sectors

I have bad sectors on my WD HDD 350GB?
What causes this?
I install my windws 7 from a Disc image using powerISO and it worked great with no prbolems on my HDD.
Later on i had to replace my mobo! so i decided to reinstalled windows again only this time with the same image but on a DVD as a boot DVD.
After the installation my HDD started making some weird noises like kinda like scrathcing noise for like 5 secs and then it would stop.

I like to know if formatting my HDD will frix that problem about the bad sectors

when i install my OS from the virtual drive image it was fats and now i installed from DVD and after install the performance whent down a little and it said it had bad sector i checked it with the Data Lifeguard Diagnostic for Windows from WD website and it failed the full test.

again will formatting my hdd fix this?
Whats caused this?
Coulda be that the DVd might have some corrupted files.?

I am thinkin a bout istalling windows on another extra hdd and formatting the 360 one and after that reinstalling windows again on the original HDD?

I dont mine loosing all my stuff i dont really have any program i need i already got all my data backed up.

ALL hard drives will die.

Yours is dying. The bad sectors are not necessarily a symptom, but the noise is a warning. Many new drives ship with bad sectors.

Formatting will not address bad sectors.

The DVD cannot, in and of itself, cause bad sectors or corrupt files. I/O errors can cause corrupted files but do not cause bad sectors. Bad sectors can cause I/O errors.

A perfectly good drive will experience Bit Errors. The smaller the drive, the less likely a bit error will occur on any single transaction, but it is still possible.

Think of your HDD as an old-fashioned vinyl LP. Playing the LP causes wear and tear. Same with the HDD.

thanks for the reply.

Well i guess the power outrage in my room is what caused this.
Since the cold weather came up my parents started to use this little plug in the wall heater that draws too much power and sometimes it turn out all the power from the little hall on my house and my room and also my parents room.

and then i have to pot the power back on from the power box on the wall.