I bought my laptop at Best Buy about 5 years ago with Win7 installed on it, and I immediately backed up the OS at the beginning before doing anything else. After about a year, the hard drive died. So I bought a new hard drive and reinstalled Win7 from my backup disks. The backup turned out to be faulty, with missing programs and driver signatures, so I spent a few months figuring out what to get to patch it up and make it work. That was about 4 years ago. About 1 month ago, I was frustrated with Win7, mainly because Windows Updates would not function no matter what I did to repair it. So I upgraded to Win10. Now I have other problems and have been on another site trying to get it all straightened out. I often am advised to just do a clean install of Win10. So now I have downloaded the Win10 ISO using Media Creation Tool and burned it to a disk. Now you know my computer history!
With all this being said, I'd like to know if I can do a clean install of Win10 from the DVD. I've been told different things. I've heard that I can't because installing the ISO of Win10 wouldn't have the product registration number that's needed and that I'd have to pay for that. Supposedly, it was different when I did the upgrade because Win7 was already there and had that number. But it would be different if I did a clean install. I've also been advised that Microsoft has that number and that I'd need to be connected to the internet when I did the clean install in order for MS to identify my computer as legit. But I don't have a way to be connected during installation. Windows has to be installed in order to establish a connection.
So what can I do? I'd like to do the clean install of Win10. It's ISO is on 1 disk, doesn't have all the Toshiba and Best Buy software on it that came bundled on my computer (and my backup) and may even be the source of some of my problems (Best Buy app was uninstalled, but all of it's registry components are still there and I can't remove them). Plus, Win7 is a faulty backup and I'd have to put all the "patch" programs back in place to make it work right again. At the same time, I know Win7 better since I've had it so long, and only have had Win10 for a month. All in all, I think I'd like to go with Win10. But can I "clean install" it from the DVD without being connected to the internet? Will my current hard drive still have that 25 digit registration number on it somewhere to allow Win10 to be seen as "legit"? I'd like to know these things before I try anything so I don't create an even bigger mess.