Unattended install of Windows OS is easy.... Unattended install of OS + Software Applications = You will need to either create an image that will be used for the installation from a prior manual build process using software such as Ghost or use a Windows Server system and RIS or WDS depending on the Server version and the OS to be pushed to systems.
If this is a single computer or small group of computers and you dont have a Windows Server to set up RIS or WDS on then creating individual images is the best way to go. If you have hundreds or thousands of systems then you will want to use RIS or WDS to push an install to a system unless all workstations are the same exact model or you have say less than 10 different hardware configuration models in place to have 10 individual images for.
I have used RIS in the past and you are essentially able to boot a workstation system off of PXE Network Boot service that the RIS server is hosting and select an image to push to the workstation, the system then pushes the installation clean to this workstation as long as the network adapter driver matches to that of the RIS image. Otherwise RIS fails to connect between the Server and workstation. * One trick that I did was I bought some cheap PCI Intel Pro 100 Managed Network Adapters and so the systems that were not the Intel Pro 100 chipset, I would install this adapter temporarily to PXE boot and push the image to the workstation. Then when the system is done, remove this adapter and have the system run off of its other Broadcom etc adapter.
BUT.... With RIS and I believe also with WDS, you still need to activate the Windows Installation with Microsoft. Also you need to take a single system that is built the way you want all others built and use that to create the installation image for the other systems to be exactly configured to, however they are all running on their own Windows OS keys.
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If going with an Image off of an external drive or DVD discs, the only problem you can run into is that its a static image and so all systems built from that image have the same Windows key. If there is a difference in hardware between the system that the image was created on and the system to take the image you can run into problems of a Blue Screen of Death or if your lucky will only have to reactivate Windows with Microsoft within 30 days. Using an external drive is easiest as for your not swapping out DVD1 for DVD2 etc until all discs are installed of the spanned image so its the most realistic unattended installation where discs would require you to check on its progress and remove and insert the next disc etc. Also depending on what is installed it doesnt take long to end up with an image that is 9 DVD's spanned for 36GB for example with a build of Windows 7 64-bit with all updates up to the creation date of the image + MS Office + Accounting software + other software, printers, configurations, etc for a 45 minute build process if using external USB 2.0 hard drive etc to push the image.
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Lastly the only drawbacks to RIS and WDS is that if you do this over the network during a time of the day when others need bandwidth and are running a 100mbps network, you will bring the network to its knees for a period of time. My employer did not want to justify upgrading to Gigabit Switches at this location and so I had to perform RIS installations after normal business hours for a while. But then I got my boss to authorize purchase of another Windows 2003 Server license and so I was able to host my own private network in my office that was isolated from the main LAN and I was able to basically pick up a system, set it up on the workbench, PXE boot it, authenticate with server, select image, push image, activate Windows XP Pro key, and then run MS Updates when connecting system to normal network. Then deliver it to the user about 1 hr later built like new from the RIS image. Over the private LAN it took about 20-25 minutes to push a 16.5GB image to HP SFF DC5000 Pentium 4 2.8Ghz systems with 512MB RAM and 80GB HDD's, and the private lan was flashing full bore to push the image to the system.
And the biggest PRO of using RIS or WDS is that you can have multiple systems ( workstations ) receiving this image installation at the same time. ( Although due to network bandwidth limitations, the more that are getting imaged, the longer the process takes to complete! ) The most I had getting an image at once was 20 workstations all getting a fresh install. These systems were part of an internal training room where the business hosted its own internal training program for existing and new employees and an instructor would demonstrate and users would be in this large room at their individual computers and follow along and learn how to do their jobs better or a new software application that is being pushed out to the 7 locations of the business. So when the course was done, I'd wipe them clean of any personal info and have them ready for the next training as clean workstations. I basically started the 20 at the same time on like a Friday and then would check back into work on Saturday and activate the XP keys and have the training classroom I guess you could call it ready for class that Monday all fresh ready to roll.
