Create a Bootable Windows Vista USB Drive
Get your hands on a USB drive  that’s at least 3GB in size. You’ll also need a Windows Vista installation disk.
Format the USB Drive
- Insert the USB drive into your computer.
- Right-click Computer in the Start menu and then select Manage.
- Select Disk Management under Storage in the left column of the Computer Management window.
- Right-click the USB drive in the bottom center section of the Computer Management window and select Format. Warning: Make sure you select the right disk to format. Formatting a disk will erase all data on it.
- Change the file system to NTFS and then click OK to format the USB drive.
- Wait for the USB drive to be formatted. The formatting progress will be shown in the Computer Management window.
Set the USB Drive’s Volume to Active
- Open the command prompt with administrative privileges by going to Start, All Programs, Accessories, and the right-click Command Prompt and select Run as administrator.
- Type diskpart in the command prompt and then press enter on your keyboard.
- Type list volume and the press enter.
- Find the USB drive in the list of volumes. In this example Volume 3 is the USB disk I’m using. Select the volume by typing select volume X (with X being the volume number of the appropriate USB drive) and then press enter.
- Set the volume as active by typing active and then press enter.
- Type exit and then press enter.
Create a Boot Sector on the USB Drive
- You’ll need a utility called bootsect.exe which can be found in any Windows Vista DVD in the boot folder. Copy bootsect.exe from a Windows Vista installation disk and past it in the C:\Windows\System32 directory in your computer.
- Once you copied bootsect.exe from a Vista installation disk to the System32 folder on your computer, type bootsect /nt60 X: (where X is the drive letter of the USB drive) and then press enter.
Copy Windows Vista Installation Files
- Insert a Windows Vista installation DVD.
- Open Computer from the Start Menu.
- Right-click the DVD drive the Vista install DVD is in and select Explore.
- Copy all of the files from the Vista installation DVD and past them in the USB drive.
Now you can install Windows Vista from a USB drive !