"As notebooks, netbooks and slates get thinner, smaller, and more power-conscious, optical drives that can read and write to a bootable DVD have now become a peripheral device rather than a built-in. This makes it difficult to install software from a DVD, and even more problematic when you want to wipe the device and install a new OS. For these devices, installing software that you download as a compressed .iso file from a SD card or USB flash memory device is fast and cheap and a great alternative to buying an external optical reader. This is particularly useful to developers since most (if not all) of the software available via MSDN and DreamSpark is only available for download in the .iso format. Unfortunately there are not a lot of turn-key tools out there for burning from an .iso to a USB memory device.
Microsoft has created the Windows 7 USB Download Tool which is really nice if your .iso is a Windows 7 operating system, but it fails when you try to use it with any other .iso. While searching for a work-around, I found this great blog post by Rafael Rivera with an explanation for why the Windows 7 USB Download tool won’t work with every .iso file:
In a few seconds your .iso file will be fixed! Then launch the Windows 7 USB Download Tool pointing to your .iso file and your USB memory device will be formatted and your .iso file unpacked so it will act just like a DVD. If installing an application, just navigate to the setup file and double click. If you are installing an OS, then first you have to make sure your boot priority setting in your BIOS lists the USB device first, then DVD and finally your hard drive. Then restart your computing device and it should start booting from the USB device. As an added bonus, installing programs from flash memory devices, particularly USB devices goes MUCH faster than from DVDs.
I had missed this the first time (and later...) times it went around the Net... sigh. So many inter-toobs, so little brain space... :/
Anyway, since so many of my devices now don't have CD/DVD drives I want to keep this suggestion, and reference to Rafael's utility, handy.