Recently I posted an error which I got while installing Google Chrome in my office workstation. In that I assumed that the setup is trying to download an executable which is the actual Chrome installer. My assumption is right. Here is how I concluded my assumption. I opened the Fiddler2, which is an excellent HTTP tracking tool. Then I ran the initial small Chrome Setup. I saw the installer is trying to download a file from http://cache.pack.google.com/chrome/install/149.27/chrome_installer.exe
I am using Windows XP Professional with SP2. I am assuming the above URL has nothing specific to the OS edition. I think the string "149.27" in the URL could be the browser's minor version number. The Chrome version which I installed is "0.2.149.27".
Disclaimer: I don't know what harm will happen if you use the file from the above URL.