Depends in your faith in the quality of the new drive. Quick format just writes the file system and erases any existing files. If the drive is 100% error free you are done. Full format actually checks that it can access the drive surface on all recognized sectors. If you have any doubts that there may be a bad sector and you want to catch it before you write anything to them, then you can either a) full format before you use the drive or b) download the manufacturer's disk diagnostic software and use that to do a full destructive write test. The latter is potentially better in that it can write a bad sector list to the drive itself (rather than just tell the installed OS the location of bad sectors) and activate spare sectors. If you are feeling lucky, you can quick format and load everything onto the disk then schedule a chkdsk with repair option (cmd: chkdsk [drive] /R ) at your earliest convenience. That will do the same kind of testing as a full format, except that it will just check the integrity of the files that have already been written and do a read-write test of the the free space.