The OSGeo4W stuff crept up on me quietly. Suddenly there's this cygwin-like installer that bundles Qgis, uDig, Grass, web-mapping, and all the lovely libs in one neato package. That's a win.

But I still wanted an easy way to install qgis without the use having to choose which of the packages they wanted, and set options to install, and not get confused by some of the other options in the installer. So I went on the hunt for how to do an unattended install from a set of packages (ie not from the internet).

After reading a few blog posts about installing Cygwin, I figured it out. Here's the howto. It's easy:

1. Get the OSGeo4W installer exe file.
2. Run it, and choose Advanced Install
3. Choose 'Download Without Installing'
4. Set the Local Package Directory to something like C:\osgeoPackages
5. Set your internet connection parameters to your local needs
6. Choose the packages you need. I chose qgis (in the Desktop category) and python-qgis and qgis-grass-plugin from (Libs). Choose anything else you need, dependencies are automatically selected.
7. Hit Next and wait for it all to be downloaded.

Now you have a package repository you can ship to another machine along with the installer exe file and do an unattended install. Assuming the repository is in the same place and the setup exe is in your path, from the windows CMD prompt do:

osgeo4w-setup.exe -q --local-install --root c:\OSGeo4w -l "c:\osgeoPackages\http:%3a%2f%2fdownload.osgeo.org%2fosgeo4\release"

which you can obviously put in a .bat file.

It will install all the packages you just downloaded and create desktop and start menu shortcuts. Qgis 1.0.0 is then a double-click away.