My suggestion to you would be to use (at least) Sysprep. Doing so will clean the OS and remove any identifiers that are unique to it. You can provide an answer file to the setup process that occurs when an operating system boots after being sysprepped so that you don't have to enter the information manually for every PC (except the name). Windows Automated Installation Kit (WAIK) is a useful tool for this.
You will need to clone or take an image of the "reference" computer somehow and depending on the number of times you need to use your image, you might want to think about how you deploy it. You can use ImageX to capture and apply an Windows Image (WIM) file. Applying an image is done by mounting the destination drive you you can only realistically do one at a time.
A more comprehensive tool called Microsoft Deployment Toolkit (MDT) will create an answer file, help you Sysprep and capture the image, and help you create media to deploy the image (among many other things). Microsoft Deployment Toolkit will help you with this and the creation of some media for deploying the image to a PC (ie CD or USB media), but if you want to speed things up and do multiple simultaneous deployments over a network, you'll need something like Windows Deployment Services.
Some useful resources
Technet - Building a Windows 7 image: http://technet.microsoft.com/en-us/library/ee523217(v=ws.10).aspx
Microsoft Deployment Toolkit: Mitch Tulloch has written a lot about this http://www.windowsnetworking.com/articles_tutorials/Deploying-Windows-7-Part1.html