Next, you'll want to create a recovery drive for the operating system already on your PC. If you're running Windows 7 or Vista, your PC's maker hopefully included a recovery disc with the system, or a recovery partition on your hard drive. Skip down to the "Use your manufacturer's recovery partition or discs (Windows 7 or earlier)" section of PCWorld's How to reinstall Windows like a pro for details for more details.
Windows 8 and 8.1 let you create your own recovery drive, however. Press the Windows key on your keyboard to land on the Start screen (the one with all the colorful tiles) and type "Recovery drive." A list of search results will pop up on the right edge of your screen; select Create a recovery drive and follow the steps from there. It's very straightforward. The vanilla option should fit on a 500MB flash drive, but if you're backing up a retail PC with a recovery partition provided by the manufacturer, you'll probably need a 16GB or larger USB drive.
Be warned: Creating a Windows 8 recovery drive wipes any data you may have already had on the thumb drive.
With backup and recovery drive in hand you're ready to take the plunge and install the Windows 10 Technical Preview on your PC's hard drive. Here's hoping you never need to use the backups, but they're invaluable if wonkiness does occur. If the mere idea of playing with pre-release operating systems makes you queasy, be sure to check out PCWorld's pictorial guide to all the changes in the Windows 10 Preview.
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