Platform architecture refers to 32 or 64 bit systems which strongly suggests that you have downloaded the wrong version of Win 7 and you are going to have to double check which version is installed.
As previously posted, go Start - right click on Computer then click on Properties.
At the top of the page will show Windows 7 Home Premium as well as SP1 in that section.
Lower down the page under System will display either 32 or 64 bit.
If it displays as 32 bit then you need to download the Home Premium file for x86 or the x64 if it displays as a 64 bit system.
As you said earlier that you were unable to select Properties in Safe Mode (don't know why because I can), another way to check if you are using a 64 bit system is to go Start - Computer (or click on yellow folder in the system tray) - Windows (C) - you will have a folder for Program Files as well as a one for Program Files (x86).
The Program Files folder is for 64 bit based programs and the (x86) is for 32 bit based programs.
I don't know what it would display as if you are just using a 32 bit system as I've never been inside of one.