Do you want to install Windows to the USB drive and run it from the USB drive (also called Windows To Go), without affecting the operating system already installed in the hard drive? PowerISO can install Windows 10 /11 to USB drive, thus you can experience the new operating system without changing the existing operating systems. 

To do so, you need a Windows ISO file for Windows 10 or Windows 11, which can be downloaded from Microsoft official website. You also need a USB flash drive or a portable SSD drive with the storage capacity of at least 32GB. All files in the USB drive will be deleted when installing Windows, please backup the files in the USB drive if needed.

Please follow the steps to run Windows from USB drive,

Step1: Install Windows to USB drive

1. Start PowerISO (v8.6 or newer version, download here).

2. Insert the USB flash drive or portable SSD drive you intend to install Windows on it.

3. Click on the USB toolbar icon, and select "Install Windows to USB drive..." from the popup menu.

4. PowerISO requires system privilege to write the USB drive, please confirm the UAC dialog to continue.

5. The "Install Windows to USB Drive" dialog will popup.

Click "Browse" button to select the Windows 10 or 11 iso file. After you have selected the Windows setup ISO file, PowerISO will list all Windows editions in the ISO file, please select the desired Windows edition which you want to install from the list.

Select the USB drive from the "Destination USB drive" list. If multiple USB drives are connected to the computer, please make sure that you have selected the correct drive. Check the option "List USB hard drives" if the USB flash drive or portable SSD drive is not listed. 

Choose the proper boot mode from the list. The available options are BIOS and UEFI. For most modern computers, UEFI mode is suggested. If your computer doesn't support UEFI or you want to get better compatibility, you can select the option BIOS. Please remember to enable the CSM support in BIOS settings if you select the BIOS mode and your computer supports UEFI.

6. Click "Start" button to start Installing Windows to USB drive. Before writing files to the USB drive, PowerISO will show a dialog prompts you that all data in the USB drive will be overwritten. Please click "OK" to confirm and continue. PowerISO will erase all partitions in the USB drive, create and format the new partitions, then copy Windows systems files to the drive. You can see the the detailed progress information in the message list.

9. After all files and the boot information have been written to the USB drive, you should receive a message indicating that the Windows has been installed to the USB drive successfully.

Step 2: Configure the BIOS to boot from USB drive

You should now reboot and go into the BIOS configuration to boot from USB. Instructions for doing so vary wildly from system to system, but generally entail the following:

1. Reboot the system.

2. While booting (before Windows starts loading), get into the BIOS configuration screen by hitting something like F1, F2, Delete or Escape. Hotkey instructions are generally provided on the screen.

3. Go to the section that contains your boot devices.

4. With your USB drive plugged in, the USB drive should be listed. If it isn’t, your system might not support booting from USB. Assuming that it is supported (as is the case with virtually all modern hardware), promote your USB drive to the primary boot device. If you selected the BIOS mode when installing Windows, please enable the CSM support in BIOS settings. 

5. Exit from the BIOS configuration, saving all changes.

Please notice that you can seriously screw up your system by providing incorrect BIOS settings!

Step 3: Boot and run Window from USB drive

Assuming that you properly configured your BIOS and your USB drive supports booting,  Windows should run from the USB drive. The first time you run Windows from the USB drive, you need finish the Windows setup process and activate Windows if needed. 

If it isn’t working, then double-check the following before making a scene:

• Is your BIOS properly configured for booting from the USB device? (Is the USB device listed and does it have top priority?) Please enable the CSM support if you installed Windows in BIOS mode.

• Have you correctly prepared the USB drive in step one? (Restart the procedure.)

• Does your USB drive properly support being booted from? (Try another one!)

• Try another boot mode when installing USB drive. Usually the UEFI mode should work, but if it doesn't, you can try another boot mode.