Is there any way to tell a desktop it has the right hard drive but does not?

not sure what you mean. if you have more than one drive and were hoping the 2nd one would boot then you may have to switch things around first.Your BIOS (usually F2 at system start) lists yor disk drives. Because newer systems want BIG hard drives, your BIOS LOOKS at the BOOT sector and decides if it a) what type it is (big 4k sectors or small sectors) and then b) can it boot it c) if its connected ok. It will then place it in the LIST of boot devices. You can change the ORDER of which ones boot first. ** note if you have inserted a NEW drive that has PREVIOUS data on it then the BIOS may treat the drive differently. You must BLANK any previously used drive to allow the BIOS to see the drive as Ready to be used as a new system disk. hope thats what you meant. If your drive is not blank and you just cant get the computer to recognise it, you may have to put it back into an old pc and copy off the data that way(in other words the newer BIOS doesn't get the data reading order right)

Hi Freetowitnis

i see you are new to all this some older desktops did use drives side by side however. it is rare these days to have this configuration. most are stacked one on top of the other. many other things have changed as well we have SATA now not IDE drives. so you need to do some further studying.

The pc specs can tell what type of drive can be use with the pc and if you are using sata hdd a lot of sata hdd are compatible with your pc on the market for example I hope this help with your question

also came out of dell desktop same model #

No.