Re-installing Windows 7

You needed to create a backup of your hard drive while you had it. Water under the bridge.

The OEM Windows activation code? Why would Dell have supplied you with one?

Anyway see if the answer at http://www.dell.com/support/contents/us/en/19/article/Product-Support/Self-support-Knowledgebase/software-and-downloads/dell-backup-solutions/Media-backup?dgc=SM&cid=60916&lid=777082590&linkId=33369211 is useful

Thanks for your comments.  I had been at that Dell site before but it wasn't helpful.

The OEM Windows sticker inside the battery compartment contains an activation which is not recognised by MS.

Fortunately I found some sites which have links to digitalrivercontent resources although officially digitalrivercontent no longer supplies ISOs for Windows 7.(windowsxlives.blogspot.co.uk for example).

I managed to download an ISO and put it on a stick using Rufus.   This installed Windows 7 Home Premium using my OEM activation code but at that point there was  no internet connection so it couldn't check validity.  Note that to get it to boot from the stick, other boot options should be disabled.

I had to find a driver to get an internet connection.  The Dell driver site gave me some help although many of the drivers offered were irrelevant and I was still missing 4 which I found elsewhere.   All drivers seem to be working now.

When I checked the validity of my validation code on line it told me that my installation was not genuine.  Fortunately, when I followed the lengthy telephone validation process it was successful and I now have a legitimate Windows 7 installation.

I hope that the above might be helpful for others who haven't the necessary backups available when their system is corrupted.

You don't understand what I told you.

You went through a lot of trouble for nothing. 

If you had bothered to read that Dell webpage, you wouldn't have had to activate Windows.

Sheesh.

Firstly it is a Dell Latitude and these are Business models which usually come with Windows 7 Professional and not Windows 7 Home Premium. Check you are installing the correct Edition of Windows 7.

If you have downloaded the wrong installation media then delete the EI.cfg file within the sources folder of your Windows 7 Bootable USB. Then clean install Windows 7 Professional opposed to Windows 7 Home Premium.

Next since you are using Microsoft Installation Media opposed to Dell Installation Media OEM System Locked Preinstallation will not be applied. This can however manually be applied. 

For Windows 7 follow my guide to download installation media, clean install and activate using the proper Dell OEM SLP method:

http://dellwindowsreinstallationguide.com/windows-oem-faqs-and-downloads/#7601 

Once you have Windows 7 installed, online and activated follow my instructions here to generate a genuineticket for Windows 10 activation:

http://dellwindowsreinstallationguide.com/the-initial-clean-install-of-windows-10-using-a-faded-windows-7-oem-coa/