Win7 wont validate or reinstall after hard drive replacement

My first thought is a clean install. I know it's a lot of work, but it can make a world of difference.

I had a similar problem to yours after using Acronis to image a drive over, but it was with Office 2007. For some reason, the phone activation system claimed my installation key was invalid and refused to activate it. Finally, I was able to activate it over the Internet.

If a new product key won't work, a clean install may be the only solution.

The Upgrade install will not clean install without installing again over the top.  The orange Box Set is MAK 3 times.

The other thing I find is that the OEM Key from SP1 will not install on Pre SP1 and vice versa.

I am certainly trying to avoid having to do that.  I am also concerned about the implication.. that there is something fundamentaly different about the Win7 I get when I go back to "factory config" and the Win7 I get off the official MS win7 DVD.   I tend to keep computers a long time, will I have to go back to "factory fresh" every time a hard drive fails? Kind of negates the value of doing image backups.   The install message "Windows won't install on this hardware" makes me think there IS something Dell did to win7 to get it to work on the XPS .     

The other thing I find is that the OEM Key from SP1 will not install on Pre SP1 and vice versa

The system came with SP1 installed so I assume the key is valid for SP1, MS tried a new key as well.

When you say the "Upgrade will not clean install without installing again over the top" what do you mean?  It wont' install over a system already running SP1 or that it will replace the current SP1 files ( which is what I want) .  Also what is the Orange box set reference?

Thanks for the response.

Retail version of Windows 7 has two main primary type of licenses – full or full package product (FPP) and upgrade, where the most obvious differences between full and upgrade versions are different prices for full and upgrade license, and customers have to possess an existing Windows license to be eligible for upgrade license.

Officially, Windows 7 Upgrade version only allow an user to “upgrade” from a previous version of Windows operating system, via “in-place upgrade” or custom install, which replaces old Windows. Even if upgrade path from some versions of older Windows cannot perform “in-place upgrade”, and require user to perform a custom clean install, but it only means that user has to start the Windows 7 installation from within an existing Windows, and choose “Custom Install” during the course of Windows 7 setup.

Windows 7 Upgrade license wants to see an installed and activated copy of Windows XP or Windows Vista before installation is allowed. As Windows 7 setup does not ask for an existing CD or DVD disc of Windows, thus if user full formats and wipe XP or Vista installation so that the drive is empty and blank before using the upgrade disc, setup no longer able to see any existing installation, and will return “Invalid Product Key” error message.

OEM COA and Key will not work with Retail Versions of the WIN7 Disc and Vice Versa.

Retail Keys will not work with the OEM version of windows.

A Genuine DELL Restore DVD for WIN7 if the Machine Came with WIN7 Will not ask for a key

and will automatically activate using the Certificate stored in the BIOS rom.

If you have an Orange Box Upgrade or Other Retail Single upgrade you can boot from the Disc

and install windows (without entering a key).

After it is installed you Boot into windows.

Then Enter the Key

It will make a windows.old folder that you can delete.

Then go online and activate.

Microsoft is not trying to stop people from upgrading they are trying to stop people from installing more than 1 copy of windows using the same key.

The Exception to this is the Orange Box version which allows 3 installs from the same key.

A Genuine DELL Restore DVD for WIN7 if the Machine Came with WIN7 Will not ask for a key

I've used OEM keys with retail discs; the only key that wouldn't activate was from a Family Pack. (It would only activate with an upgrade-type install, not a fresh one.)

Good info on the different type of loads and keys.  I had started out building an ISO image from a link the MS tech support guys typed in while they had remote control of my machine..but when they saw it would take 2 hours to download they logged off to let me finish the download and try the install.  The download hiccupped and the image was corrupt but I found a link to a WIN7 image online and used it.... I wonder if the one MS was linking to was an OEM image and I linked to a retail download...  That was the image that gave me "can't run Win7 on this HW " message, so I dont think it had even attempted validation yet. .

I reloaded from the factory default restore DVD's this AM, I will see if it validates ( it activated automaticly) .  

The comment of :

A Genuine DELL Restore DVD for WIN7 if the Machine Came with WIN7 Will not ask for a key

and will automatically activate using the Certificate stored in the BIOS rom.

Is intriguing...My root problem is that my fully licensed, legal and official Win7 OS wont pass validation. Validation must be looking at some finite set of parameters to decide what is Ok and what isn't. Is this BIOS parameter one of them?  Can't imagine why it would have changed.  

I'm unsure of the algorithm, but once Windows is activated validation follows.

I have a collection of Windows 7 PCs (Home, Professional, and Ultimate in OEM, upgrade, retail, and academic versions), but I confess I've never used a restore disc. The Fortune 500 company where I'm working on contract makes extensive use of Dell machines (I'm using a T3500), but they're set up with regular Enterprise versions of Windows.

The purpose of BIOS activation is to spare the user having to manually activate Windows. In the event of it failing, the user has the option of calling the 1-800 number, which has only failed twice for me, once with a corrupted Office 2007 and again with the third install of a Family Pack disc.

Microsoft is usually quite friendly about giving you another key.  The only time they did not is when I had gotten a chinese pirated DVD from Ebay that looked Legit.   I paid for and was sent a new disc from microsoft with a key.

It was called windows 7 get legal edition.