When I install this version of photoshop, I type in the serial number which allows me to install the program, then once installed it asks for another serial number in which I type the same number in only to be told it is an invalid serial number.
I was wondering if anyone is able to help me figure this problem out.
You've bought an upgrade version and you've entered your upgrade serial number.
The second serial number requested is one from an earlier version of Photoshop which made you eligible to buy the upgrade.
If you don't have an earlier version serial number then you've bought the wrong version. You need to return the upgrade version and buy the full version.