Hi, I don't think this falls under the normal installing on external... I have OSX and winXP boot camp on the Air and I want to install 7 on my external, which is formatted as GUID with 5 partitions, my OSX data, Windows data, and 10.5.6 & S.L. install partitions and now a new Windows 7 partition for Windows 7... question is will this work so I can press Option at startup and select the Win7 partition to boot up ala Boot Camp? Cheers! Ok, to perhaps make things easier, I'm installing Win7 on my Bootcamp partition on my MacPro, is there any way to then clone that partition to my external drive and boot from that on the MBA?