Windows 8.1

So I want to format my C drive since somehow my SSD only has 20 GB left out of 120. But I have windows 8.1 and Im worried that if I format the drive, I won't be able to re-install windows again with the same product key for the OS. If I format, will I need a new copy Win 8.1?

Is your windows OEM or did you buy it?

Just contact Microsoft, I'm pretty sure they have to deregister the key then it can be used again.
There might be a key that works on multiple PC's

if you re-install it on the same system, then you will be totaly fine.


Is that how the keys work? I can imagine that people would somehow abuse that

As long as you dont change the motherboard, you will be totaly fine.
You can re-install your system as often as you like.

But if you replace your motherboard, or a platform switch from AMD ot intel, or what not, then it will be a diffrent story if you have an OEM key.
Then you have to call MS indeed.

But as long as you just use it on the same motherboard, you will be totaly fine.

You should be fine. If anything should come up. you call an automated number, answer a few questions. They deregister the old and activate the new.

Ah alrighty nah I'm using the same mobo. I knew you had to buy a new copy if you get a new mobo though. You told me that last year january! :P Yeah I remember that, is that weird?

well i dont think its weird lol.

actually its the opposite. If that key only works for one computer and never for another, the MS is forcing you to buy multiple copies of Windows essentially. Its not the old days where OS keys and keys for games could be used to install them onto multiple computers at a time.

I bought it at bestbuy. So I have that package with 32 and 64 bit Windows. I didn't like the idea of an OEM, so I'm pretty sure what I bought at BB is a full copy.

I had to call microsoft recently as I was reinstalling my windows 8 pro licence that I bought when it came out for 40$.

They could not get y key to work with the automated phone thing so they had to remote access to my comp in order to enter some command lines and other stuff I don't remember (I did not care either)

Of course I uninstalled the whole thing after.

To make things easier you could first try the built-in reinstallation routine that Windows 8 has. Under Start it's called "remove everything and reinstall windows".

Ahhh. I've never had issue with using the same 8.1 key on different machines..... Worst case its a phone call to the Microsoft Activation hotline when it notices a severe change in hardware.