Alright, this is the third time I've tried this, and I STILL don't have an answer, so here I go.
I have a serial number for Adobe Master Collection CS3, and I think it was originally bought for a Mac, but I'm not sure. Anyway, I was trying to install it on my Windows 7 PC. When it came to the part where I need to enter a serial number in the installation, I entered it, and it let me install it. But now, when I opened up Photoshop, it asked me to do it again, and when I tried to enter it, it rejected the serial number. I know it's paid for, and not a pirated serial number.
I tried the chat, and they told me to call. I tried calling, and they told me to go here. (Adobe needs a better system). So, here I am. I need an answer. Anyone?