Installing Windows 7 from a USB
A USB storage device needs to be 4 GB or larger if you want to use it as a Windows 7 installation source. This is because the x64 installation files are approximately 3.2 GB in size and the x86 installation files are approximately 2.5 GB in size. You use one architecture’s installation files only when preparing a deployment from a USB storage device. The USB storage device should use the FAT32 file system.
To prepare a USB storage device as an installation source for Windows 7, perform the following steps:
1. Connect the USB storage device to a computer running Windows 7 or Windows Vista. Ensure that the storage device has no data stored on it that you want to keep (or that you have moved such data to another storage device) because this procedure removes all existing data.
2. Open an elevated command prompt and type diskpart.
3. At the DISKPART> prompt, type list disk. Identify which disk connected to the computer represents the USB storage device.
4. At the DISKPART> prompt, type select disk X where X is the number of the disk that you have identified as the USB storage device.
5. At the DISKPART> prompt, type clean. When the disk is clean, type create partition primary.
6. At the DISKPART> prompt, type format fs=fat32 quick. When the format is completed type active and then exit.
7. After you have completed these steps, copy all the files located on the Windows 7 installation DVD to the USB storage device.
8. Configure the BIOS computer on which you want to install Windows 7 to boot from the USB storage device. Attach the USB storage device and then reboot the computer to start installation.