Here is how install Windows from a USB device, like a flash drive. Windows XP, 7, 8, 8.1 If you want to install Windows XP,7,8,8.1 from a USB device, you’ll need to get those setup files from the DVD to the USB drive. Regardless of whether you have a Windows DVD you need to get on a flash drive, or a Windows ISO file with the same goal, the following tutorial will help you get the Windows installation files properly copied to a flash drive so you can get on with the installation process. Requirements: A flash drive (4 GB for 32-bit, 8 GB for 64-bit) A Windows DVD or ISO file Access to a working computer (with a DVD drive if you have a Windows DVD) with Windows 8, Windows 7, Windows Vista, or Windows XP installed Important: If you have a Windows ISO file and want that on a flash drive, start with Step 2. If you have a Windows DVD and need that on the flash drive, start with Step 1. Step 1 Create an ISO file from the Windows DVD You can create ISO file from DVD using one of the free software for creating ISO file like ISODisk. Next is how to get that ISO file onto a flash drive. Step 2 Download the Windows 7 USB/DVD Download Tool from Microsoft and then install it. link This free program from Microsoft properly formats your flash drive and then copies the contents of the Windows installation ISO file you have to that flash drive. Note: Don’t worry that this program has Windows 7 in the title. This program works perfectly well with Windows ISO files and can be used in Windows 8, Windows 7, Windows Vista, or Windows XP. -Start the Windows 7 USB DVD Download Tool program. You should be able to find the shortcut on the Desktop, as well as in your Start menu or on your Start screen, depending on which version of Windows you installed the program on. -Click Browse on the Step 1 of 4: Choose ISO file screen. -Locate, and then select, your Windows ISO file. Then click or touch Open. Click or touch Next. -Choose USB device on the Step 2 of 4: Choose media type screen. Note: As you can see here, there is also a DVD option. While it doesn’t do us much good in this case, since the end game is to get Windows setup files on a flash drive, you could also use this tool to burn a Windows ISO image to a DVD or BD disc. -On the Step 3 of 4: Insert USB device screen, choose from the drop-down box the flash drive or USB-connected external hard drive you want to put the Windows setup files onto and then touch or click Begin copying. -Click or touch Erase USB Device if you’re prompted to do so on a Not Enough Free Space window. If you don’t see this, don’t worry, it just means that your flash drive or external hard disk is already empty. Important: If this message didn’t make it apparent, you should know that whatever data you might have on this drive is going to be erased as part of the process of getting the Windows setup files copied. -On Step 4 of 4: Creating bootable USB device, just wait for the Windows 7 USB DVD Download Tool to prepare the drive and copy the Windows installation files to it. The first Status you see will be Formatting, which will take anywhere from a few to several seconds, depending on how large the USB drive is that you’re using. Next will be Copying files which could take anywhere from 15 to 30 minutes, possibly longer, depending on which Windows ISO file you’re working from, as well as on how fast your flash drive, USB connection, and computer is. The next screen should say Bootable USB device created successfully with a Status that says Backup completed. -You can now close the Windows 7 USB DVD Download Tool program window. The flash drive, or other external USB drive you’re using, now has the necessary files on it to install Windows and is also properly configured to be booted from. Step 3 Boot from the USB device that you just created to start the Windows install process. Tip: If the Windows setup process doesn’t start, it’s very likely that you’ll need to make boot order changes in the BIOS Tip The Windows 7 USB DVD Download Tool formats the USB drive as NTFS, a file system that many UEFI based computers will not boot from when on a USB drive. To work around this issue, do this: -Copy all of the files from the flash drive to a folder on your PC. -Format the flash drive manually, using the older FAT32 file system. -Copy all of the files from the folder you made back to the flash drive. Windows 10 Users: You can use same Windows 7 USB/DVD Download Tool from Microsoft to get Windows 10 Technical Preview ISO image to a USB drive for installation.