Original, undoctored O.S. that came with the computer: Windows 7 Home Premium V3Y2W-CMF9W-PGT9C-777KD-32W74 After upgrading to "Ultimate" using Bit Torrent Dell Windows 7 Ultimate imaged DVD: Windows 7 Enterprise (Note this is the not "Ultimate") 33PXH-7Y6KF-2VJC9-XBBR8-HVTHH Microsoft Office Professional Edition 2003 VJXRC-M64VX-2XYXD-PCKJ9-GJKVM Adobe Photoshop 7 Serial: 104512096738466876962783