Apple set free OS X Lion to the general public yesterday. The only way to upgrade to the new OS was by way of downloading it from the Mac App Store. Apple has received its fair share of criticism for making Lion download-only. This limitation makes it so that if you have multiple Macs at home, you have to download Lion on each PC (yes, they are personal computers after all) separately. We’re going to solve this issue for you today, by making a Bootable Flash Drive of Lion! The procedure requires a medium level of computer-related knowledge. You’ll need the following items: Access to the Mac App Store and a working Apple ID so you can purchase and download Lion An empty flash drive with at least 4 gigabytes of memory: An 8GB flash drive would be recommended. Once you are in possession of the abovementioned items, follow the guide written below! How To Make OSX Lion Bootable USB Flash Drive Step 1: Download OS X Lion from the Mac App Store. Step 2: Once downloaded, go to the Applications folder and find the copy of Lion you just downloaded. Step 3: Right click on the downloaded file and select “Show Package Contents”. Step 4: Go to “Contents” and jump inside the “SharedSupport” folder and you’ll find a file titled “InstallESD.dmg”. Copy this over to the desktop. Step 5: Plug in a USB flash drive to your Mac having at least 4GB memory. We highly suggest going ahead with an 8GB one just to be on the safe side. Step 5: Now open up “Disk Utility” and drag InstallESD.dmg from the desktop to the left-hand sidebar. Select the attached USB from left side and click on “Partition” tab. Step 6: Select “1 Partition” from the Volume Scheme dropdown menu. Choose “Mac OS Extended (Journaled)” from the left. Step 7: Now click on “Option” at the bottom.Select “GUID Partition Table” and press OK. Now click on Apply at the bottom right to start formatting.. (NOTE: This is will erase all data on your USB flash drive) Step 8: Once the drive has been formatted, click on “Restore” (it’s right next to where you clicked on “Partition in Step 5). Step 9: Choose USB drive you plugged-in in Step 5 as “Destination” with the InstallESD.dmg file as “Source”. Step 10: Click Restore and type in your password. This will create the intended Lion bootable USB flash drive Step 11: Reboot your Mac with the USB drive plugged in. Hold the “Option” key on your keyboard when you hear the iconic OS X startup chime. You can now boot into your Flash drive from there. Step 12: Follow the on-screen instructions to install OS X Lion. You may then follow Steps 11 and 12 to install Lion on all your Macs.