Follow the guide below for reinstall Windows 7 from scratch. It also gives download links to digital river .iso files. These require phone activation, so it is best you use the Dell DVD instead.
OK, I have a DELL inspiron n5110 laptop here which I have erased the OS partition. The OEM and restore partitions are intact. I would like to restore the factory state windows 7 home.  At boot time, I tap f8 to get to the system recovery options and enter an admin user/pass. When I get to the System Recovery Options, I believe I should see "Restore Dell something-something" - Not seeing it. I imagine this is due to installing another OS on the OS partition? Is there anyway to make this happen via command line, or some other means? Or do I need to get a recovery DVD from Dell?   Thanks for help!
Attempting to restore windows 7 home