This wikiHow teaches you how to turn a USB flash drive into a tool that you can use to install or run a computer operating system. This is especially useful when you want to install an operating system (like Windows) on a computer that doesn't have a DVD/CD reader. You can make a USB flash drive bootable on a Mac or Windows computer using the Terminal program or Command Prompt (both are free). If you want to create a bootable flash drive for the latest version of Windows 10 or Windows 7, use the Windows 10 or Windows 7 installation tool to format the USB flash drive. Keep in mind that you don't need to use a flash drive if you want to install a new version of Mac OS.
Step
Method 1 of 4: Using Command Prompt on Windows Computer
Step 1. Plug the USB flash drive into the computer
The USB flash drive must be plugged into one of the rectangular USB ports on the computer case. Flash drives can only be inserted in one direction so don't force them to insert if they're upside down.
You must have a USB flash drive with a minimum capacity of 8 GB to accommodate most operating system installation files
Step 2. Go to Start
Click the Windows logo in the lower left corner.
Step 3. Type command prompt
The computer will search for the Command Prompt program.
Step 4. Right-click Command Prompt
It's a black box at the top of the Start window. A drop-down menu will be displayed.
- If there is no right-click button on the mouse (mouse), click the right side of the mouse, or click the mouse using two fingers.
- If your computer uses a trackpad (not a mouse), tap the trackpad with two fingers or press the bottom right of the trackpad.
Step 5. Click Run as administrator in the drop-down menu
Step 6. Click Yes when prompted
Your decision will be confirmed and Command Prompt will be opened.
Step 7. Enter the "partition" command
Do this by typing diskpart, and pressing Enter.
You may need to confirm this decision before you can proceed
Step 8. Bring up the list of connected drives
Type list disk into Command Prompt, then press Enter.
Step 9. Locate your USB flash disk
Check the size (in GB), name, or flash drive font to identify it.
- If you can't recognize the flash drive, remove it, then run " disk list ". Next, plug the flash drive back in, and run the " disk list " command again, then check which disks are missing the first time you run the " disk list " command.
- Flash drives are usually at the bottom of this menu.
Step 10. Select the flash disk
Type select disk number into the Command Prompt. Replace the words " number " with the number of the flash disk as shown in the list. Next, press Enter key.
Step 11. Erase the contents of the flash drive
Type clean and press Enter.
Step 12. Create a new partition on the flash drive
How to do it:
- Type create partition primary, then press Enter
- Type select partition 1, then press Enter
- Type active, then press Enter
Step 13. Format the flash drive
Type format fs=fat32 quick into Command Prompt, then press Enter.
If an error occurs when creating a USB flash drive, repeat this process using the quick fs=ntfs format option
Step 14. Specify the letter for the USB flash drive
Type assign and press Enter key. A confirmation message will be displayed in the Command Prompt window.
Step 15. Close Command Prompt
Now the USB flash drive has become bootable, which can be used to place the operating system ISO file or image on the computer's hard drive for installation on another computer.
Method 2 of 4: Using Terminal on Mac Komputer
Step 1. Plug the USB flash drive into the computer
The USB flash drive must be plugged into one of the square or oval USB or USB-C ports on the computer case. Usually, a flash drive can only be inserted in one direction so don't force it to insert it if it's upside down.
- If your Mac uses a USB-C port, the USB-C flash drive can be plugged in any position.
- You must have a USB flash drive with a minimum capacity of 8 GB to accommodate most operating system installation files.
Step 2. Make sure you have the ISO file
If you want to create a bootable USB flash drive on your Mac, you'll need to have an ISO file (or an image file, if you're backing up your computer's hard drive) ready to drag and drop into Terminal.
The way Mac handles bootable flash drives is not the same as Windows in that you can create bootable flash drives, which you can save for later when you use Windows
Step 3. Open Spotlight
Click the magnifying glass icon in the top right corner. This will bring up a search bar.
Step 4. Type in terminal
Mac computers will look for the Terminal application.
Step 5. Double click Terminal
It's a black box in the middle of the Spotlight search results. The Terminal application will open.
Step 6. Open the list of connected drives
Type diskutil list into Terminal, then press Return.
Step 7. Look for the USB flash disk
Look for the USB flash drive that has been plugged into the computer, then check the name of the flash drive under the " IDENTIFIER " heading. Usually a USB flash drive is placed under the "(external, physical)" heading at the bottom of the Terminal window.
The name of the flash drive under the " IDENTIFIER " heading is usually " disk1 " or " disk2"
Step 8. Select the flash disk
Type diskutil unmountDisk /dev/disknumber into Terminal, then press Return. Make sure to change " disknumber " with the name and number " IDENTIFIER " of the flash disk (eg disk2).
Step 9. Enter the formatting command
Type sudo dd if=, but don't press Return yet.
Step 10. Drag the ISO file into the Terminal window
Click and drag the ISO file (or image file) that you want to use to boot from the flash drive into the Terminal window. The address of the file will be copied into the Terminal command.
You can also type the path to the folder where the ISO file is stored
Step 11. Press the Spacebar
By doing so, at the end of the file address will be given a space as a space to type the next command.
Step 12. Enter the next command
Type in of=/dev/disknumber bs=1m, then press Return. Again, replace " disknumber " with the number of the USB flash disk (eg disk2).
Step 13. Type in the password
This is the password used to log into your Mac computer. When typing, the password letters will not appear in Terminal. This is normal.
Step 14. Press Return
Once you do, the password will be sent and the Mac will start creating a bootable flash drive with the selected ISO or image file.
The process to complete can take several hours. So, keep Terminal open and Mac computer plugged into a power source
Method 3 of 4: Using Windows 10 Installation Tool
Step 1. Understand the right time to use this method
Windows 10 Installation Tool is a program that places Windows 10 installation files into a USB and makes the flash drive bootable. This is only useful if you are using a Windows computer to create a Windows 10 installation flash drive.
Step 2. Visit the Windows 10 installation page
This page provides tools that can be used to make a USB flash drive bootable.
Step 3. Plug the USB flash drive into the computer
The USB flash drive must be plugged into one of the rectangular USB ports on the computer case. Flash drives can only be inserted in one direction so don't force them to insert if they're upside down.
You must have a USB flash drive with a minimum capacity of 8 GB
Step 4. Click Download tool now
It's a blue button in the middle of the page. Once you have done this, the installation tool's setup file will be downloaded to your computer.
Step 5. Run the installation tool
Double-click the installation tool file you downloaded, then click Yes when prompted.
The installation tool is placed in your browser's default "Downloads" folder (e.g. Desktop)
Step 6. Click Accept at the bottom of the installation tool window
Step 7. Check the box "Create installation media"
This box is located in the center of the window.
Step 8. Click Next
It's in the lower-right corner of the window.
Step 9. Click Next again
Doing so will select the computer attribute as the attribute to be applied to the installation file.
If you want to change your computer's default settings in terms of language, edition, and architecture (e.g. 32 bit), uncheck the "Use the recommended options for this PC" box, then change the values you want before clicking Next.
Step 10. Check the box "USB flash drive"
The box is in the middle of the window.
Step 11. Click Next
Step 12. Select a drive
Click the name of the drive you want to use.
Step 13. Click Next at the bottom of the window
The tool will start formatting the flash drive for the Windows 10 installation. The process involves deleting any files that are still on the flash drive, making it bootable, and adding the Windows 10 ISO file.
Method 4 of 4: Using Windows 7 Installation Tool
Step 1. Plug the USB flash drive into the computer
The USB flash drive must be plugged into one of the rectangular USB ports on the computer case. Flash drives can only be inserted in one direction so don't force them to insert if they're upside down.
You must have a USB flash drive with a minimum capacity of 4 GB
Step 2. Get the Windows 7 ISO file
How to do it:
- Visit the Windows 7 download page.
- Enter the Windows 7 product key.
- Click Verify
- Select the desired language.
- Click Confirm
- Choose an option Download (64 bit or 32 bit).
Step 3. Visit the Windows USB/DVD Download Tool page
This page provides tools that can be used to make a bootable USB flash drive and place the Windows 7 installation files onto it.
Step 4. Click Download
It's an orange button in the middle of the page.
Step 5. Select the desired language
Click the check box to the left of the version of the tool you want to use. For example, if you want to choose a version with US English, look for a tool that says " US " at the end of its name.
Step 6. Click Next
The blue button is at the bottom right of the page. The selected tool will be downloaded to the computer.
Step 7. Install the Windows 7 USB/DVD Download Tool program
Double-click the downloaded file, then follow the on-screen instructions.
Step 8. Run the program
Double-click the "Windows 7 USB DVD Download Tool" icon on the desktop. This will bring up a new window.
When prompted, click Yes before you continue.
Step 9. Select the Windows 7 ISO file
Click Browse, then click the downloaded ISO file and click Open.
Step 10. Click Next
The button is at the bottom of the window.
Step 11. Click USB device
This button is in the lower right corner.
Step 12. Select the USB flash disk
Click the name of the flash disk that you want to use.
Step 13. Click Begin copying
The button is in the lower right corner. Doing so will make the USB flash drive bootable and copy the Windows 7 installation files onto it.
