Any 2.5" 9.5 mm Serial ATA notebook drive will work.

Thanks ejn63, are the connectors the same though, I looked at another laptop and my GF's laptop and the connectors seem different on all three...?

Thanks ejn63, will check that and see...

:emotion-21:

For SATA drives, yes - they're all the same.  Many systems have a proprietary interposer or caddy that you will re-use on the new drive.

If there is a connector, it isn't soldered.  It is easily removeable if it's needed.

If you see two narrow L-shaped connectors, those are standard SATA. 

If the drive you've purchased has pins rather than these, it's PATA and won't work.

I have not purchased a drive and it looks like it is an unusual HDD which Dell no longer supply,, why not just tell me this in the first place...???

Because it isn't true.  the system uses a bog-standard, 2.5" 9.5 mm SATA notebook drive.

There is nothing proprietary, different or unusual about it.