I have ios 6 in my pc but i downloaded it from another pc?

I have ios 6 in my pc but i downloaded it from another pc.
And that ios 6 is not opening in itunes in my pc
I want to upgrade my iphone
what to do? Do i have to download it again from my pc?

Do you even know that ios 6 is only for apple devices… By the way whom are you tring to fool ahh?