Install Windows Vista from a high speed USB 2.0 Flash Drive

I've been thinking about writing a post about "How to install Windows Vista from a USB Flash Drive" for a while but just never got around to doing it. What got me thinking about it was a post on Josh's board (windowsconnected.com) about running WinPE from a bootable USB Flash drive and it seems to me like there's be a lot of folks that would want to install Windows Vista entirely from a USB Flash drive as well.

WHY INSTALL FROM USB FLASH DRIVE?
Why would someone want to install a client OS from a thumb drive instead of a DVDROM or over the network? One reason: Performance. Installing Windows Vista from a high speed USB flash drive is in my experience the easiest & fastest way to complete a Windows Vista install. This is much faster than using a DVD, gigabit ethernet, or possibly even some external USB 2.0 hard drives, due to differences in access speed & transfer rate. To put this into perspective, y'know how installing Windows on a Virtual PC virtual machine from an .ISO CD image is really, really, really fast? Imagine something roughly just as fast, except for doing installations of the OS on to actual workstations.

STEP-BY-STEP INSTRUCTIONS
Here's some step-by-step instructions on how we do this, some of which was adapted from Josh's instructions, again, kudos to Josh.
Acquire an ultra-fast USB 2.0 flash drive
The drive I and my coworkers recommend is the Apacer 4GB Handy Steno USB Flash Drive HT203, 200X Hi-Speed USB 2.0. It's the fastest USB 2.0 Flash Drive that we've found - it has a read speed of 25MBytes/sec. & a write speed-14MBytes/sec and also works great as a ReadyBoost cache. You can get them from $56.99 each:
http://www.directron.com/ht2034g.html

Incidentally, once you've got Windows Vista up and running, you may want to consider getting an ultra-fast SDFlash card, installing it into your laptop or desktop, and leaving it there as a ReadyBoost cache. Why? It can't hurt and they're so cheap that it's worth getting. I personally got a SDFlash card for every one of my machines - the A-DATA 2GB Secure Digital Memory Card, 150X Turbo SD Card has a read

speed of more than 22.5MB/s and a write speed of more than 15MB/s. You can get them for $19.99 each:
http://supermediastore.com/adata-2gb-sd-secure-digital-card-150x.html
Format the Apacer Flash Drive
Run CMD.EXE and type the following. Note: This set of commands assumes that the USB flash drive is addressed as "disk 1". you should double check that by doing a list of the disks (type "list disk") before cleaning it. If you have multiple hard drives, like an SDFlash drive or a Multibay drive, you could end up wiping your second drive using this command.
(This was a warning that Josh added to his post along with the following commands that I copied from him, so kudos to Josh)

1. diskpart
2. select disk 1
3. clean
4. create partition primary
5. select partition 1
6. active
7. format fs=fat32
8. assign
9. exit
   

Copy Windows Vista's DVD ROM content to the Flash Drive
Simply issue the following command to start copying all the content from the Windows Vista DVD to your newly formatted high speed flash drive.
xcopy d:\*.* /s/e/f e:\

And that's it. Boot up the machine, have it boot off the USB drive, and watch how fast the installation completes. If you thought Windows Vista installed quickly before (usually 20-25 minutes per install of Windows Vista Ultimate Edition) then let's see how you like having Windows Vista install in less than 5-10 minutes. The slowest part of the install will probably be the computer waiting for you to type in information in the setup fields, and even that can be automated using the Windows Automated Installation Kit.