Creative Cloud install on PC after Mac?

I purchased a license fromAcademicsuperstore for Creative Cloud and installed it on my Mac. I understand that I can install on two computers, so I now want to install it on my PC desktop. The file that I used to initiate the install on the Mac is a .dmg file, so I tried to download the PC equivalent, and I was told that my license code had already been used. What do I do?

Thanks