The Air has always needed and had the ability to download files to support USB-DVD, without which the Air could not boot Windows DVD.
Yours should still at least try to download or create a Boot Camp 4.0 driver disc anyway, just not the DVD driver, and the Apple drivers normally get installed after Windows is installed and updated, not for pre install.
A Boot Camp driver ("Windows support software") disk can be created with either Boot Camp Assistant 4.0 or 4.0.1. The difference is in the availability to create a "Windows 7 install disk" from a Windows 7 ISO. Boot Camp Assistant 4.0 does not have this option; 4.0.1 does.
Copying the Boot Camp 4.0.1 assistant from the 2011 MacBook Air to a USB stick, and moving it to the the 2010 MacMini an running it from there worked. This saved time because I had the Windows 7 ISO on the MacMini. If I had the Windows 7 ISO on the MacBook Air, I could have created the Windows 7 install disk (a USB stick) from there.
Copy and repair permissions?
In the past, people would extract the program from the installer with Pacifist to "install" it.
There are differences, Lion tech notes even mention it will be different on different hardware.
This procedure will install a version of the OS X Lion that is compatible with the Mac it was created with. Using this Lion system with a different kind of Mac may produce unpredictable results.
Thanks for your reply. The reference you metioned addresses installing Lion. I've had no problems doing a clean install of Lion from a USB stick or a SD card with an image restored from InstallESD.dmg. I'm interested in installing Windows 7 in a similar way, and for now that appears to be limited to new hardware such as the Mid 2011 MacBook Air. It's not a show-stopper though because I can install Windows 7 from a DVD.
A Windows 7 installation image on either a USB stick or an SD card will boot on a Mid 2011 MacBook Air.
The same image won't boot on a Mid 2010 Mac mini; however an OS X Lion installation image on either media will boot on either computer.
In all cases the media is formatted FAT32 for a Windows 7 install (using DISKPART on Windows), and HFS Journaled for an OS X Lion install (using Disk Utility on OS X).
I'd like to understand why, and if it's possible to install Windows 7 from a USB stick or an SD card on a Mid 2010 Mac mini.
I'd like to second this notion. I removed the optical drive from my MacBook Pro to make room for another hard drive. And now there is no way for me to install Windows, short of re-installing my optical drive. PC users can boot and install Windows from USB drives, why can't Mac users do the same? Is there something in the new MacBook Air and MacMini EFI that allows you to boot a USB drive?