Booting from a SSD in an external case

[mato2252]

Hello, I am going to buy a macbook air 13" and I have an SSD (with windows 7 installed on it) from my old PC. I would like to put the SSD to an external case (should it be with or without AC power? on usb 3). Can I boot into it? Thanks for all the help!

 

[cin19]

Even you can buy one this USB 3.0 to 2.5” SATA III Hard Drive Adapter Cable http://www.newegg.com/Product/Product.aspx?Item=N82E16812400542&cm_re=sata_to_usb_adapter-_-12-400-542-_-Product because the 2.5" format drive does not need more power so that the adapter doesn't need the AC power, but you can buy one with or w/o the AC power.
You can use the ssd as the external drive but can't use it as boot drive.