I have windows 10, but i have some problems, i think i will need to replace old hdd with new one, but i don't know if i will be still able to install windows 10. I don't know how microsoft will know this is still my pc.
Most likely. But if you wanted to be sure (or more sure!) then...
Get a new HDD and install your old OS on it. (7/8.1)
Make sure it's activated then go through the upgrade first-then-clean install process.
If this doesn't work out you still have your old drive which you can re-install.
Microsoft recognizes that HDDs fail and this won't/shouldn't affect your re-install.
But nothing is for certain and plenty of qualifying Windows 10 upgraders have had difficulties.
I first did the W10 upgrade over my W7 disk and then afterward I did a clean install of W10 on another disk. Both installs were activated.
Ok thanks. Also i didn't get any activation key, but my windows is activated.
The licensing information is written into your motherboard's ROM, as far as I know. That's the only piece of hardware that you can't replace without losing Windows.
And what if i need to replace it? I won't have any windows anymore.
Only recent motherboard bios's have OS info, also if you are a builder, the motherboard you choose will not have embedded product codes. If a change of hdd or ssd is required then Microsoft's activation servers will remember and allow a clean install.
I just rebuilt my computer, but I didn't upgrade my CPU yet. That is planned for later this month. So the HDD's and SRAM and Mainboard will remain the same but will I be allowed to change the CPU and still have Windows activated?
Yup. I have been doing some more reading and I think I was wrong earlier when I said the licensing data is written into the mobo's ROM, but from all I can gather, you can replace any piece of hardware except the mobo and still use Windows.
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