The download is the installer. It's a self-installing exe file. You just run that to upgrade. The Apple download site usually auto-detects that you have 64-bit Win 7 and downloads the correct file. The file is always named iTunes64Setup.exe and the latest version is the one at the apple download site. That looks like this for me:
Rock and a hard place...
Self installer would be great if I could get on the internet...
Without iTunes i can't tether my iPhone - without tethering my phone I can't get iTunes.
On the PC that has iTunes I can't download the installer as I already ahve the latest version.
If I could download the file to USB then take it with me to the offline PC - I could instal and then tether