Remove the cover of HDD?

Yes, a seen a lot of HDD with out there covers on. I seen one that melted because it was placed to close to the CD-RW unit.

Not yet..why should i..if is broken..buy a new one..i dont know how to fix it

hdd means

I never tried to do it with my own hard disk, however I have seen many opened hard disks, its a CD like thing called media (3 to 5 of them) placed in a cylinder shape manner, its inner structure is not complex, the main things inside are the heads and the media where the data is written

Yes I have. IBM originally developed what is known as the Winchester drive technology where the read/write head parks on the platten when not in use and skims the surface when in use, without making contact. The HDD consists of a spindle with notches. Plattens are seated in the notches. Each platten has a corresponding read/write head. These plattens are formatted to be separated into tracks and sectors. Tracks continue from platten 0 to platten "n" where the value of n is the total number of plattens. The spindle is connected to a motor, which rotates the spindle at fairly high speeds, typically 5600 revolutions per minute. Improvement in media density and read/write head per square mm. Hard drives have grown in capacity from 5 MB in the old PC/AT to literally hundreds of GB in the new generation machines.