Replacing E5420 HDD

If the drive still works correctly, you can try cloning it (some drive makers provide software;  you'll need a cable or external case to attach one of the drives to the system to do the job).  More often, the drive is too far gone for that -- if so, you will need the set of recovery media you made when you received the system, or if you didn't do that, to contact Dell and order that.

Thank you for the reply,

The drive is still working but has developed bad sectors, which means it will sooner or later get worse... I think I can still manage to create recovery media. Is there a how to guide to creating and restoring media through Dell Backup and recovery software.

regards

Alok

Yes, there is.

http://www.dell.com/support/contents/us/en/19/article/Product-Support/Self-support-Knowledgebase/software-and-downloads/dell-backup-solutions/Dell-Backup-and-Recovery