2008 MacBook Air Can't Boot OS X Snow Leopard USB Install Drive I have a 2008 MacBook Air (MB003LL/A / MacBookAir1,1 / A1237 / 2142), and I am trying to reformat it with OS X 10.6 Snow Leopard, using the retail install DVD image snowleopard_10a432_userdvd.dmg restored to a USB flash drive with Disk Utility. I do not have an external DVD drive to use.

Whenever I try to boot, I get a "no" sign after a few minutes of waiting after the Apple logo. 
If I boot it in verbose mode, I get:

USBMSC Identifier (non-unique): AF429H02YE09000451 0x154b 0x7a 0x1100
AppleIntelCPUPowerManagement: initialization complete
Still waiting for root device
Still waiting for root device
Still waiting for root device


...and so on.

Does anyone know how I can solve this issue?
It can't find the kernel files.  When you turn on your Mac make sure you  pressing and holding the the "Option" key then selecting the USB flash?

If you are still having difficulty, then the creation of the USB flash disk didn't go so well.  I am assuming that you have a good DMG image of the Snow Leopard DVD. 

You can't just "copy" or restore the image to the USB flash, you have to format and partition it first.  See How to Create a Bootable USB Drive With OS X Snow Leopard for a good tutorial on how to do just that.  

Once you are done, you should be able to boot from the USB flash and install OS X.