iTunes 64 bit won't even start under Windows 7 x64 HP

I have a Vaio EB that came with Windows 7 Home Premium 64 bit. I just got iPod touch as a gift and when I turn it on the first time, it was asking to connect to iTunes.
I never have iTunes installed in my vaio before as I thought windows media is enough, and since this is my main computer now, I decided to download the windows version of iTunes 9.1.1 64 bit instead of updating the one in my old Mac (which has iTunes 7, and the minimum version for iPod touch is iTunes 8).
When the file is downloaded and when I tried to run it, nothing happened. No error codes, no notification, nothing. I tried to download again, the apple web only allows me to download the 64 bit version, but then same thing happened with second installer file. Can anyone help?

 

Download the 32-bit version. It will run in a compatibility layer in any 64-bit version of Windows. You will NOT be able to tell any difference between the two.

 

It turned out the installer file was messed up during download for unknown reason.
I did try downloading the 32 bit version from a 3rd party location, since Apple website would auto detect your location and OS, it won't let me download the 32 bit version (and for a good reason too since after I successfully downloaded it, Apple insisted that I use the 64 bit version instead and won't let me go through the installation process).
So I downloaded the 64 bit version again for the gazilionth time but using GetRight download manager this time (I downloaded the 32 bit installer using this program too), and sucessfully downloaded and installed it.
Funny thing, the file downloaded through IE and Google Chrome (that didn't work) is 96,129 KB while the file downloaded through GetRight (that worked) is 96,125 KB so it's actually smaller, where in h*ll that extra 4 KB came from??? and the download source is the same.