How do I install Windows 7 HP Upgrade via download?

I’m trying to upgrade from the RC. I’ve downloaded the three files, which are the .exe for installing it, “setup1.box” and “setup2.box”. When I try to run the .exe, it pops up a message saying,

“The application cannot find one of its required files, possibly because it was unable to create it in the folder. Please make sure that the folder in which this application was downloaded is accessible and not read-only.”

I made sure it was read-only, but it still doesn’t work. I need this done soon, because the RC expires tomorrow.