All computers must have at least one hard drive. At the moment of selecting hard drives two factors come into play: capacity and rpm speed. You want to ensure that your new computer has enough hard drive storage for all your computer software as well as all the stuff you create and store there.

Most computers are now typically sold with a 500 GB hard drive, which allows users to store thousands of pictures and videos and a large collection of Itunes songs.
It seems obvious to say that computers need at least one hard drive. However, if the hard drive is very large, a good tip is to partition the main hard drive in two parts: the main part for the system files and the other part for storage. This way if the computer crashes, it is always possible to retrieve the files from the second part of the hard drive.

On the other hand computers work also with two or more hard drive: a system set up with more than one hard drive should have also the RAID card that enables an equal distribution of the data between the hard disks in order to prevent hard drive failure. Among the Raid choices pc doctor recommends the RAID 5 that allows distributed parity but can only work with at least three hard drives.

Some smaller systems, such as game machines and handhelds, don’t require a hard drive. Instead, they use special memory to store information. In the case of game systems, storage sometimes takes the form of memory cartridges, which plug into the game’s console. As with memory, you can always add more hard drives to your computer. The only limitation is the space inside and outside your computer.

Laptop hard drives are very small and come in the same size of desktop drives. Generally, you cannot add a second hard drive to a laptop internally, unless it is a high end gaming laptop, but you can add an external hard drive or use a PCMCIA storage device to expand the laptop’s storage capacity. The best bet in this case is to get a large hard drive in your laptop in the first place.

Avoid buying any computer with less than a 1 TB hard drive, as hard drive will slow down when their capacity arrives to the 80% of its full size. An optimal situation will be if an hard drive is always 50% full in order to work flawlessly.

Since 2015 a new class of hard drive, called Solid State drives is going to replace the mechanical hard drives. Solid State Drives are much faster than the traditional hard drives but they are still too expensive to get.

For the hard drive, the idea is to buy a nice roomy hard drive when you get your computer, one that will store all your data for years to come without worrying about upgrading. So do pay attention at the moment of buying a computer: make sure that it has enough room and think to the future use of your machine, when possibly the number of files will increase.