You need to fully activated your existing windows 7 or 8 license. Then use the iso to do an upgrade first and just skip the step to key in serial. After the successful upgrade, your computer will connect to internet and auto activate your windows 10. After the activation is successful, if you want to clean installation, use the reset function to wipe your computer clean.

That's what i understand from various sources from Google, correct me if I am wrong.

p.s. No, all your previous Windows key cannot be used for Windows 10 activation.

you can, like what horns said. But you need to do upgrade once first and activate Windows 10. Then only do a fresh installation from the USB key.

i think only changing a major part like motherboard and hard disk (from my own experience) will alter the HardwareID and make the key not working.

So your fresh install Windows 8.1 pro and activated successfully? If yes, then you should just download and apply all the windows update and wait for the logo to appear.

we know what you want. but to have a working activation for Windows 10, you need to follow what me and horns suggest.

1. Do upgrade from existing activated Win7 or 8.
2. Make sure the upgrade Windows 10 is activated.
3. Do a clean install (wipe clean clean your SSD in the process) for Windows 10 again.
4. Your Windows 10 should be auto activated now.

If you are using Pro version, it will remain Pro version, same for Home version.

Yes, it will prompt you for product key but if you are upgrading from an activated windows, you can just skip the product key section. After the successful installation, it will auto activate your new Windows 10.

The version will be the same as your current windows 8.1 - Pro will get Pro back and Home will get Home (info from one the Microsoft technical blog but i myself not tested it yet).

yes, you can skip it all the way....

not possible to uninstall all your existing programs to free some space? I think it is about time you clean up your hard disk.

what internet line you are using? My home streamyx 8mb might take some time to download. So i download now in office with Unifi, done in 10 mins.

Yes, horns already confirmed.

serial key is not needed during the installation as Microsoft is not going to issue you one for those upgrading.

fat hope.. the most a trial version will be included like what you can find in new laptops.

seriously? a genuine version? Heard the rumour but din see any confirmation.

Manage to upgrade one of my home desktop from win8.1 pro with media centre edition (genuine version). After successful upgrade and the auto activation, i try checking the product key with Key Finder program - surprisingly the product key is the generic key for Win10 Pro floating in the internet now.

Actually for those thinking of fresh install and instead of upgrade in order to get a fresh clean OS hard disk, i think the following will suffice:

1. Install by upgrade method.
2. Choose "Do not keep anything".
3. After successful upgrade, just use the disk cleanup wizard to remove the old windows system file and the temporary installation files.

I did that for my win8.1 pro desktop and the system hard disk seems pretty clean after the whole process. Dun think i will redo a fresh installation.

have you tried using Win 8.1 driver to update? For those hardware that do not come with Win10, I just download and use Win 8.1 drivers, so far all working.

check your volume and install or reinstall audio driver. Need to install video codec if only video has no sound.

This post has been edited by Cynox: Aug 4 2015, 04:00 PM

it will download the 64-bit version. My office 64-bit windows 7 also pop up this "Optional update" with size of 2,699.0MB.

The key you found is just a generic key if you are upgrading. Actually you dun even need to key in the key if you clean install the second time - just skip the input key screen.

My second installation on activated Windows 10 doesn't ask for key at all during the installation. It will just auto activated.

you sure? I thought only changing the motherboard will require a new key. So if you install it to new SSD, a new key should not be requested, i.e. the same activation code will be automatically used from the upgrade process.

EDIT: Btw, anyone encounter problem with the File Explorer? When I copy large file from one hard disk to another (20-60GB), the copying process windows will suddenly disappear and the copying process just done half way, no error message come out and program not freezed. Have to redo copying again. Very annoying. It happens randomly.

This post has been edited by Cynox: Aug 9 2015, 10:43 AM

ok, thanks for the info. Coz Horns mentioned from his experience, changing hard disk doesn't count. I did change my motherboard once and have to call MS helpdesk to get a new code for Windows 8 previously.

on the contrary - I think my Macbook Air has much better battery life than in Win7. Maybe you need to tweak your power management settings.