There are several ways to create a bootable USB media if you have an ISO. You can also do this using an SD card if you have a USB adapter for the memory card. For Windows 7 a 4GB drive is fine, for later you will need more than 4GB.
Microsoft Windows 7 USB/DVD download tool
The easiest method is probably the Microsoft USB/DVD download tool
This is simple and easy to use, and should work with Windows Vista ISOs or later.
ZOTAC WinUSB Maker
This is another nice tool from http://forums.mydigitallife.info/threads/47012-ZOTAC-WinUSB-Maker-Official-Support-Thread, and works with Windows Vista ISOs or later.
If you don’t have the ISO or want to do this manually, you can also use diskpart to prepare the drive and then copy the contents over. This is the way I normally end up doing it for some reason, the advantage being that you don’t need any other tools if you are running a Windows OS. Risk of formatting the wrong drive if you don’t know what you are doing with diskpart, so be careful.
Format the Drive
Run cmd.exe as Administrator and type the following:
- list disk (Note which one is your USB disk – make sure you get the right one!)
- select disk 2 (assuming that it was listed as disk 2)
- create partition primary
- select partition 1
- format fs=fat32 (Note: Quick format does not work)
Copy the files
Mount the ISO or insert the DVD, and then copy the Windows files to your drive.
Modify the below example depending on your drive letters:
xcopy d:\*.* /s/e/f e:\
OR easier using Robocopy:
Robocopy d: f: /e
Note that you can do something similar on Linux using http://www.pendrivelinux.com/