Extract the installer. To the default location of the desktop is fine:
Run the extracted Acrobat installer and enter the serial number:
Once installation is complete, you may need to run the program from the start bar or a shortcut from your desktop:
When you run it the first time, be sure and "SKIP" the "Sign in Required" dialog:
There may also be a "terms and conditions" dialog. To this it's ok to click "accept".
After this is complete, the program may automatically update. If it doesn't, you can click "Help > Check for updates". After this, you'll need to close Acrobat Pro for the updater to run. There is usually two updates to run.