Upgrade 200 XP machines to Win7 Pro

I am about to upgrade around 200 XP machines (laptop and desktops) to Windows 7 Pro. I would love to hear some of the best options for this? Any suggestion would be much appreciated! Thanks.

There is only one option. That is a Clean install of Win 7. Even if you start the upgrade install from inside XP it will still only install 7 clean in a new Windows folder on the drive, saving the old XP install to a folder called something like Windows.Old.

There is No direct upgrade path from XP.

Microsoft Volume Licensing Home Page

Volume licensing.