I've seen lots of questions on the internet on how to do this, since the Steam bootstrapper can be a nightmare on slow or inconsistent connections. So, you'd really just like to get the install files for the Steam client and download them through a download manager. This is possible.
In addition to Steam, you'll need Wireshark.
I'm going to be doing this on OSX with a Steam client update, but the methodology is the same for Windows with one minor change, which we'll get into later.
First, get Wireshark. www.wireshark.org
Step two, load wireshark. Select your interface. On OSX, my ethernet is en0 and my wireless is en1. On Windows, it's more verbose and looks like this:
In addition to Steam, you'll need Wireshark.
I'm going to be doing this on OSX with a Steam client update, but the methodology is the same for Windows with one minor change, which we'll get into later.
First, get Wireshark. www.wireshark.org
Step two, load wireshark. Select your interface. On OSX, my ethernet is en0 and my wireless is en1. On Windows, it's more verbose and looks like this:
You may have to run Wireshark as root or admin, depending on your OS. This is normal.
Then click Capture -> Start.
Wireshark should begin populating with packets even if you're not really doing anything. This is normal.
Now, we need to filter for exactly the packets we're looking for. In the filter field, we're going to put in http.request.method == "GET" That should filter out most of the packets.
Now, with that open and running, launch Steam. The screen will begin to populate.
See those entries for public_all.zip and bins_osx.zip? That's what we're after.
What steam is doing here is literally just using http to download .zip files from their servers. It's exactly the same thing your web browser does.
Click on one and examine the hypertext part of it. That's a regular URL to the file we need. Do this for every packet that is a GET request for a .zip file.
If you click on the URL, it should begin downloading in a web browser. Use your favorite download manager to stop, resume and recover.
When the files are completed, for OSX you simply copy them into /Applications/Steam.app/Contents/MacOS/package/
For Windows, you copy them into c:\Program Files (x86)\Steam\package (or your respective package directory under your Steam folder).
On launch, Steam should check for, then install the new files silently and your Steam client will be updated or installed.
