There has been a dramatic change in deployment technology between Windows XP v/s Windows 7 (and Vista).

In the old days, you could choose to do unattended installs, or clone. To prepare for either you edited a text file and away you went. When installing, you supplied that file to the DOS based setup program that took compressed DLLs from a network installation point and uncompressed them to disk for Window's first boot. When you cloned, the same file (or very similar) was used to prepare the system for cloning. 

But today there is no choice. All installs are a clone, even if you wouldn't normally know it. Also gone is the DOS based part of setup, and the old text file. Now you boot WinPE and it copies a base image to the boot disk, which upon reboot immediately starts Windows OS in installation mode whereupon it identifies additional drivers needed and configures the system for normal run-time, gets it's instructions from a XML file that you must use a toolkit to create. 

Deployment of windows is basically wrapped up in a whole new deployment ecology, using the Microsoft Deployment Toolkit (free) and the System Center Configuration Manager 2007 for large scale deployments.

However, if you don't want to invest in WDT 2010 you can still hack out a unattend.xml file for Win7 like you used to edit an unattend.txt file for XP. See the downstream pages for XP and Win7 for details on each.
Subpages (1): SysPrep and Images