Hi. Unfortunately, I was unable to find an answer for my question.

Our company has a task to reinstall OEM and retail purchased machines (Dell and HP, preinstalled Windows 7 and 8) (for example when a person leaves the company or in case of malware).

The idea we have it to take a machine of each model and image it (either using tool like Acronis or capturing WIM files with DISM). Meaning that the image will be taken still in the Out of the Box state (no sysprep). And later we will apply these images to the machines with the matching model (which had OEM Windows installed)

What will happen from license/product key side if we start deploying these images to machines (with dism)? Will it ask for activation (as OEM machines come preactivated) or will take the BIOS/UEFI stored OEM key automatically?

What if instead of imaging machines we will simply deploy using recovery wim files supplied for a given model?

Can we rely on OEM licenses instead of going to Volume Licensing (especially as we paid for OEM)?

Thank you!

For the imaging question, if there is a recovery image already included with the machines, that would be the best one to use with DISM, since it should already be in a deployable state and it would already be designed for that hardware.

Regarding your licensing question, or specifically that you paid for the OEM version. I see this a bit and it comes down to you (basically) having purchased the wrong type of license for your purposes. If your company is to purchase computers for use in an enterprise setting, you wouldn't want to purchase the "home use" type products that HP, Dell or other OEMs normally sell. From your end, its mostly a concern due to how the license and images are handled, because you can't fully control them for deployment or repair since you don't have access to all their tools. The hardware itself is just fine, but the OEM can offer to make an image for you using the Enterprise or VLK software if you purchase it yourself. Typically these images won't have the extra bloatware, but there may be a purchase minimum in order for the OEM to put in the effort.

Thank you!

Yes, I try to use recovery images that are on drives. Works well except for HP laptops. I noticed that they have  26 GB recovery partition and 2 volumes having the same letter D on this partition (one is hidden, another not). Going to drive D: doesn't show any files - probably hidden. Will dig more or maybe someone experienced it.

I agree that reasonable  way would be to contact vendors and request deployment images. 

All will be good.  If you have a sysprep'ed OEM Dell Windows 7 and clone to another Dell computer (that originally came with Windows 7), the OS will activate against the hardware.  No issues at all (I do exactly this same thing on a routine basis).

What you can't do, however, is take a Dell OEM image and clone it to an HP OEM computer.  You would have to use an HP OEM system as the source.

Doing this is a wonderful way of legally saving licensing costs if you purchased PCs with Windows preloaded.

What happens if you clone an OEM image to a system that is not OEM?  The non-OEM system will operate just as if you installed a retail version of Windows 7 (giving you a 3 day grace period).  To activate, enter your MAK or KMS.  All is still good and legal.