I have a dell D-600 laptop which the screen has went out but works well with an external screen. I have a dell D-610 which takes the same model hard drive but when I put the hard drive from the 600 in the 610 it brings up an error message and will not let me proceed to windows. The 610 did not come with a hard drive when I got it but I did see it work so I know the unit is fine. Any help would be appreciated.:) I know I`m working with older stuff I just don't want to shoe a dead horse if you know what I mean.