He simply used the right activator, for his installed VL Version, me think, and that's for each activation task up to max 180 day's!
That's how the KMS activation works. Uou can either reactivate it manually or install the service to reactivate it on each boot. So it's forever anyway...
There is the strangest thing I still don't know the answer, I just bought the Dell Latitude 3440 laptop from Ebay with Windows 7 Home Edition already installed. I decided to put the new 1TB hard drive, and freshly installed Windows 10 Pro (1511 April updated), when the installation completed, the Windows is already activated. I don't know why, but very happy.
After further thought the only thing I can think of is someone activated Windows 10 on that computer, then went back to Windows 7, so it would not matter about HD's, if it's a fluke, please delete your post, or call MS and tell them you are a cheater, if you do not know how to delete it, just ask, I'll be happy to help you.
Are you saying it came first with Win 10 OEM, Cause I believe Windows 7 did not come with home, but Home Premium?
There isn't a BIOS key for Win 7, home premium, pro or whatever, there is a manufacturer signature. Which is identical for every PC sold by that manufacturer. The unique bios key is a Win 8+ thing.
If 10 used the 7 HP in the BIOS, then it will have installed 10 Home as the ISO contains both SKUs If it installed and activated 10 Pro, then something else happened
7 uses slic2.1 table and 8+ uses oemm and the 10 install can't use the slic table, only the oemm. You can check what is inside the bios with the OEM_Query tool from the Multi OEM Project.
The pc was licensed for 7 Pro originally by the OEM, then had 7 home premium installed, then Windows 10 Pro retail was used to install How far can we stretch this?
Weird, then yes, possibly the laptop had previously been upgraded / activated / downgraded back to 7 to sell