You don't say if you are going to 32 or 64 bit Win 7 or what OS you are using now. If you have to do a clean install, you will need the Mediadirect CD to partition. Contact Dell support if you didn't receive one with your system. Have added Dell's support site for procedures to set up MD depending on your version.
XPS8300, i7-2600, 12GB DDR3 Ram, AMD HD 6770 Video, ST2420L Monitor, WIN 7 64bit Home Premium