My existing hard drive was on the blink so wanted a bigger capacity unit to replace it, I searched throughout the Internet for the best price, I'm a pensioner on a fixed income, eventually arriving back at Amazon who offered the best deal. The unit arrived on the day it was supposed to, neatly packaged. Now, for all those people who do not know how to transfer files and have bought expensive software to help, here is a tip. Switch off your computer, clear your body of static electricity, unplug your existing DVD DRIVE and fit the terminals into the back of your new HARD DRIVE. Switch on your computer and go into disk management and format your new drive, when completed MOVE all your files from the original hard drive to your new drive, when completed go back into disk management and change the drive letter of your old drive to your new drive. Switch off your computer, swop the drives so your new drive is situated in place of the old drive, change all terminals back to the DVD DRIVE and to your new hard drive-switch on and hey presto-you've done it. Oh yes, I also chose a Samsung unit because I have a Samsung mobile phone and other Samsung products which are utterly reliable, their software is bloody awful but that can nearly always be bypassed.