I have a pc which has windows 7 license but I installed windows from an image i downloaded and it is already activated. for validating genuine microsoft, i need to entet my own product key but the necessary activation tools do not exist in my windows folder. What do?

I googled stuff but because the keywords are too broad I couldn't find a useful tool

DAZ doesn't work, activation button doesn't show up.

When I enter my original key to Windows Anytime Upgrade, I get this error

When I attempt using slmgr, I get this error

I used sfc /scannow

Now slmgr is existing, I entered slmgr.vbs -ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX (replacing X es with the cd key) the operation successful. Now I have installed Microsoft Security essentials, which means the problem is solved.

Main steps are here

1. open cmd enter
2. Enter "sfc /scannow"
3. enter slmgr.vbs -ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
4. Success