Windows 7 boot from downloaded .iso

Downloaded Windows 7 .iso off the net and want to install from USB key on old laptop (previously/still running XP) that has no CD/DVD drive. Here's what I've got so far:

• Read the instructions in this post: http://kmwoley.com/blog/?p=345 , which were quite straight forward and clear.
• Properly formatted USB key with another laptop (this one running vista), also with no DVD drive
• wasn't sure how to make the USB bootable, since my .iso was downloaded and I have no DVD drive.

Any help would be much appreciated!!

Microsoft has released a tool to create a bootable Windows 7 installation flash drive:

Windows7-USB-DVD-tool.exe ,

And Here the instructions from MyDigitalLife.

You should follow the tutorial from Microsoft titled Use a USB Key to Install Windows 7. The basic process (as outlined in that article) is as follows:

1. Launch DISKPART from the command prompt (or by going to Start->Run).
2. Select your flash drive (to list all disks, type list disk, and then select disk X where x is the proper drive number).
3. Clean the disk using the clean command. This will wipe all data on the drive.
4. Now, run create partition primary, and then run active.
5. Finally, you can format it with the format fs=fat32 quick command, and then assign it a drive letter with the assign command.

Now, you should be able to just copy everything from the Windows 7 ISO/disc into the root of the flash drive, and boot the system from the drive.

use WinToFlash to prepare your USB stick, it doesn't get any easier.