what is sysprep? how is it useful?
I often have to format/install Windows 7 on several pc's (laptops mainly)
what's the quickest way to install? DVD / USB install is slow.
You can install via USB but it still depends on the speed of the internal harddrive. On my pc with a SSD drive installation took 10 minutes with a USB flash drive.
Download the official tool to create a Windows 7 USB flash drive: http://www.microsoftstore.com/store/msstore/html/pbPage.Help_Win7_usbdvd_dwnTool
Why not create an image using a piece of software like Acronis. They have features that allow you to restore your image back to dissimilar hardware. We use it at work and it works pretty well. The only thing I usually have to do is reinstall the LAN drivers after they are initially installed. As for which is faster, I don't really know. I guess in theory, USB should be faster?