Students and alumni can get Windows 7 Professional for only $29!
Then to make a ISO DVD from the downloaded files, see this link
BUT watch out for this issue - it worked for me after copying string below to notepad
For those having issues (particularly when already running Win7), make sure that the command you are copying and pasting has only plain text. To do that, open Notepad and paste – you will see rectangles where there are weird characters (which the dashes seem to be). Replace any of those dashes with just a plain text dash (-) and try again. It worked for me on Win 7 Ultimate Eval. Below is the output:
C:\Users\me>oscdimg.exe -bC:\expandedSetup\boot\etfsboot.com -u2 -h -m -lWIN7 C:\expandedSetup\ C:\Win7.iso
OSCDIMG 2.54 CD-ROM and DVD-ROM Premastering Utility
Copyright (C) Microsoft, 1993-2007. All rights reserved.
Licensed only for producing Microsoft authorized content.
Scanning source tree (500 files in 48 directories)
Scanning source tree complete (874 files in 201 directories)
Computing directory information complete
Image file is 2520809472 bytes
Writing 874 files in 201 directories to C:\Win7.iso
Final image file is 2523011072 bytes