Windows 8.1 install says invalid product key. Help!!


Aug 1, 2015
Ok so I'm pretty new to this site, but I've looked at other people and their windows 8 problems and I can't find the answer.

I have a at least 2 year old computer that originally had windows 7. About 8 months ago we switched to windows 8.1 by wiping the whole computer *Using factory reset* and did all the stuff you have to do to get it to work. While we were setting the computer up it asked for the product key, I put it in and it accepted it. Well after we finished with everything we restart the computer to make sure everything works and while I logged into the main account the first thing that pops up is
[/ACTIVATE WINDOWSb] and I'm just like "But I already did!!!" So I retyped the key and it now doesn't work for ONLY this computer. We have used this for other computers and it works for them but not for this one. The computer itself works, though ever 30 minutes or so *Usually while I'm in some type of fighting game* a window that blocks everything pops up saying [/ACTIVATE WINDOWSb] and leaves me completely vulnerable. That isn't my only concern, I also want to get the new Windows 10 upgrade. Even though it doesn't add too much it still is a free upgrade. Well it only is for people who have Windows 8 - 8.1 and my computer hasn't been activated so I can't get it. So in short I'm just wondering if anyone can help me with this problem.

Saga Lout

Seems like it's invalid because it is in use in another machine. Where did you buy that key when you "upgraded" from the pre-installed Windows 7? Windows 8 did not suddenly turn up when you went for a factory reset. It doesn't work like that.