You can reuse this USB drive for normal stuff after you finish installing Mountain Lion. You will need to erase all of the files on your USB drive beforehand, so make sure to back up its contents first. However, if you're setting up iAtkos from Mac OS X, you can use a 8 GB or larger USB drive instead of a dual-layer DVD. A dual-layer DVD, Bluray disc, or empty USB drive (8 GB or larger): If you are setting up iAtkos from Windows, you have to write iAtkos onto a dual-layer DVD or Bluray disc (normal DVDs don't work because iAtkos is slightly too large). If you're not sure which version to use, just use ML2. You can also use iAtkos M元, an updated version that only works with motherboards with UEFI (a guide regarding motherboards with UEFI will be posted soon). This guide describes how to install iAtkos ML2. In this guide, you will write iAtkos onto a USB drive or DVD, and boot your computer from iAtkos to install Mac OS X. The standard method of installing Mountain Lion on a PC requires you to modify a retail copy of OS X Mountain Lion with Unibeast, but iAtkos already does all of this for you.

I won't go into details, but you can download it from just about any bittorrent website by using a bittorent client (it's about 5 GB in size). iAtkos ML2 (Free): iAtkos is by far the most popular distro of OS X Mountain Lion. It's preferred that you use a completely empty hard drive for this, but if your computer already has Windows installed on your hard drive, be sure to create an appropriate hard disk partition for OS X Mountain Lion beforehand (by following Step 1 of my guide to MBR partitions) (will be posted soon). However, that's only the bare minimum if you plan to install Mac OS X for day-to-day use, I recommend allocating at least 50 GB of space. Also, OS X Mountain Lion takes up about 10 GB of space on its initial installation, so the computer where you install Mac OS X must have at least 10 GB of space in its hard drive. Be sure to read the Hackintosh compatibility guide (will be posted soon) very carefully, to check whether or not your computer qualifies. However, not every computer will work with Mac OS X. If your computer already has Mac OS X Lion installed, iAtkos will just update Lion to Mountain Lion normally, without deleting any of your apps or files. It can be the same computer as the one mentioned in the previous point. A Hackintosh-compatible computer with 10 GB+ of free space: This is the computer where you will install OS X Mountain Lion. If you're using a Windows computer, it needs to have a DVD/Bluray burner (just about every DVD/Bluray drive nowadays can act as a burner, too). An existing Windows computer/Mac/Hackintosh: This is the computer where you will download and set up iAtkos.

Mac os x mountain lion installer