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Waiceca's avatar
Waiceca
Iron Contributor
Aug 17, 2026

How to manually install Windows 11 Pro from USB stick?

Built a new PC and it is fully compatible with Windows 11 hardware requirements: AMD Ryzen 5 7600X 32 GB DDR5 RAM Crucial 1 TB NVME SSD Intel Limited Edition Arc B580 12 GB ASRock B650M AM5 I...
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Wokhiosk's avatar
Wokhiosk
Iron Contributor
Aug 17, 2026

The two-partition USB method is a clever workaround specifically designed to solve a common issue when you try to install Windows 11 Pro from USB flash drive. This problem occurs because the standard Windows installation USB is formatted as FAT32, which has a 4GB file size limit. Since the main Windows 11 installation file (install.wim) is often larger than 4GB, it cannot be copied to a standard single-partition FAT32 USB drive.

The process is more hands-on than using a simple tool, but it's entirely doable.

1. Preparations:

  • A USB drive: At least 16GB in size, as Windows 11 Pro installation files are large .
  • Windows 11 Pro ISO file: Download the official ISO from Microsoft's website.
  • A partition management tool: You can use Windows' built-in tool, Disk Part, or a more user-friendly GUI tool. You can also use community-created scripts like USB_FORMAT to automate this process.

 

2. General Steps:

  • Partition the USB drive: Use your chosen tool to format the USB drive, creating two primary partitions.
  • Format the partitions: Format the first, smaller partition as FAT32 and mark it as active (bootable). Format the second, larger partition as NTFS .
  • Copy boot files: Copy the entire contents of your Windows 11 Pro ISO to the FAT32 partition. If the install.wim file is too large to fit, you can skip copying it to this partition.
  • Copy the install. wim file: Copy the install.wim file from the ISO's \sources\ folder specifically to the \sources\ folder on the NTFS partition . This is the key step that makes the method work.

 

After creating the USB drive, you can then boot from it normally to install Windows 11 Pro from USB flash drive.

The solution is to create a USB drive with two partitions:

  • A small, bootable FAT32 partition that contains the essential boot files.
  • A larger, separate NTFS partition that holds the large install.wim and the rest of the installation files.

 

This way, when you boot your computer from the USB drive to install Windows 11 Pro from a USB flash drive, the system accesses the necessary boot files from the FAT32 partition. The installation can then read the large install.wim file from the NTFS partition, bypassing the FAT32 file size limitation entirely.