Bootable Flash Drive or Hard drive to install Windows 7

Original Title: Estimating Windows 7 WIM File sizes - UFD too small for image

I was trying to capture awim file for Windows 7 to a bootable ufd, but the 16GB UFD was too small.  I reran and directed the capture to a USB hard drive.  Is there a tool to estimate the UFD size required?  Is the FAT32 format a constraint?

Can I build a bootable USB hard drive and capture the image to it so that If I boot from the USB HD instead of the UFD?

Can I install from a USB hard drive instead of the UFD?  Then I would not be limited to the USB size of 16GB or 32GB.

Question Info

Last updated March 20, 2018 Views 1,388 Applies to:

Hi Dan Hauge,


·        Do you have an ISO file for Windows 7?


Please refer the below mentioned link which will guide you through the steps on how to make a bootable Flash Drive for Windows 7.

Installing Windows 7 on a netbook


Also refer:

Windows 7: Setting up a USB bootable device for installs - Jeff Alexander's Weblog - Site Home - TechNet Blogs

Installing Windows 7 using usb thumb drive


You can use a Hard Drive, if you wish to, instead of a Flash Drive to make a bootable drive. Also, file system on the drive is not a constraint here. You can make a bootable flash drive even if it is a FAT32 file system.



Syed N – Microsoft Support
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