Is it possible to NetBoot into Windows? I have a MacBook Air (2013) and I would like to run (that is, boot into) Windows without creating a partition for it. I also want to keep it mobile within an office area, so I would prefer not to use an external HD or flash drive.

Is it possible to use NetBoot to boot into Windows via WiFi?
There are two questions here: can you netboot anything via WiFi, and can you netboot windows? 

Historically netbooting over WiFi has been problematic. This may have been fixed in recent models (my newest computer isn't). If you can netboot via WiFi you can boot anything that is netbootable.

Now for netbooting windows. Pre-EFI windows probably won't work unless you use weird tricks like using bootcamp to load a linux boot loader off another partition and use it to load ipxe from disk to load older operating systems from the network, but this makes wifi even more difficult. Netbooting WindowsPE works well but reboots at around 70 hours, Other versions of windows may be possible to net boot with iscsi but I have not tried.