Belarc Advisor 8.5 running this will reveal any Microsoft keys. Even my Windows 8.1 free upgrade showed a key. I ran it on my Windows 10 home version it also showed my Microsoft key. I am not sure this will help the thread starter but it may help others. Belarc advisor is free.
All sorts of ways to recover the keys but they're useless. The answer has been pointed out several times in this thread- reinstall 8.1, upgrade it to 10 and then do your clean install.
To Re-Iterate -- 1) You Must use AN ACTIVATED W7 or W8 or W8.1 OS (Home, Pro or Ultimate(W7)) - NOT Enterprise.
2) You must UPGRADE W10 on that system. THEN THAT SHOULD SHOW AS ACTIVATED. IF IT'S NOT ACTIVATED THERE'S NO POINT DOING A CLEAN UPGRADE FROM THAT SYSTEM AS IT WON'T BE ACTIVATED.
3) Now you can do the clean upgrade. - DO NOT ENTER ANY PRODUCT NUMBERS ETHER AT 2) WHEN DOING UPGRADE FROM OLD OS OR WHEN DOING A CLEAN INSTALL.
4) YOU CAN ONLY UPDATE LIKE FOR LIKE -- E.G HOME to HOME, PRO / ULTIMATE TO PRO. PLUS SAME LANGUAGE BASE (GER to GER for example, or GB ENG to GB (NOT US) ENG.
You should find after update you will have TWO serial numbers if it's an OEM model you upgraded from or just the generic W10 key if it's updated from a full Retail or TechNet / MSDN version.
When doing the CLEAN install at the HDD display delete all the old partitions with the previous W10 installation on. Start with Clean HDD.
I have to admit I'm puzzled why people seem to be having trouble with this. I've upgraded 7 machines now 3 ex OEM and 4 from Retail OS'es - not one has failed to activate.
Note also - Activated systems using those "Alternative KMS etc" activators ARE NOT VALID. You can install W10 but it will remain not activated. (I've tried 3 different Pirate copies as a Test - they won't activate so Ms can breathe easily - 100,000's of Pirated copies won't be flooding the net).
There is one possible scenario I haven't been able to test -- if I create the media creation tool on a machine running say W8.1 PRO and then use that to upgrade to W10 on a machine running W8.1 Home -- I'm not sure what happens -- whether the media creation tool can sort out different versions of Windows - not tested by me but could be a cause of failed activations.
interestingly, while on the subject of pirating.....MS offered A free W10 upgrade to the Chinese, for ANY OS XP etc even if it is a PIRATED copy.........with all the inbuilt DataMining that MS has included with W10 I guess China will give them a lot of data !!!
China still wins, with all those TPLINK EDIMAX TENDA NETIS etc. flooding the markets for network devices, with built-in "leaks" of sensitive data towards China...
The first impression is that Microsoft cares less about private users piracy since most of their money comes from government and big oem's contracts. Unlike 5-6 years ago, now ~90% of PCs sales already include an oem license, hence Microsoft gets it's share. But that's wrong. I believe Microsoft's goal to push Windows 10 to everybody is just 1% good intentions (you can better support one major OS version) the rest being to forever doom offline activation and with it, pirate workarounds like bios slic mods that work 100% and they can't do anything about. So they decided to let some pirates jump the boat for one year, since it's a win-win anyway. Data is the most valuable thing they can get from you. And they get plenty in Windows 10...
But back to Windows 10 activation:
If you activated your 7 or 8 versions over the phone, you will have less chances of failing activation. Otherwise, it's a lottery - you can fail it even if you followed the steps to the letter. Or you can trigger an activation limit.
I have turned off all the privacy options and disabled cortana and data mining via 2 registry hacks.....wish I had an app which showed what was ( or not) being sent to MS...
Thank you all for your assistance.
What an incredible hassle. Why Microsoft doesn't offer an easier way to generate a Windows 10 with with a legitimate 7/8/8.1 key is beyond me.