Where is my windows product key?

[smmden]

I have managed to get onto my computer by skipping entering the product key.
But i only have 28 days.

WHERE IS THE WINDOWS 7 PRODUCT KEY?
The box i got has a booklet but no product key inside or printed on the box.

 

[keynes]

did you look behind your case?

 

[DeadEyeDuk]

Haaaave you checked on the back of the tower?

 

[smmden]

oops just found it on the back of the actual PC XD

edit: Thanks. I'm stupid lol.