The first step in getting an Operating System into MDT is downloading it from Microsoft Volume Licensing Service Center (if you have access). It is very important to note the Release Date, as an Operating System can have multiple Release Dates, even without a Service Pack being added. These are typically released after Update Rollups.
When you download the ISO, make sure you save it in an organized structure, and make sure the Directory Name contains the Release Date!
You should then be able to double click on the ISO and Windows will mount it for you. No need to burn a disc or use WinZip to extract the files. If you are not sure of the Release Date, then just use the Date Modified of the files (and yes it will not match up with the Release Date from MVLSC).
Before you Import the Operating System create two folders under Operating Systems. Name the first one Media. Then a second folder matching the Operating System and Release Date. This will save you some grief later when you don’t know which version you have imported and help separate your Media from Custom Images.
When you finally Import the Operating System, change the Destination Directory to include MEDIA and the Release Date.
You can then change the Operating System name to something a bit more friendly.
Like a Boss!