I should point out that the Recovery Console is not DOS. Windows XP does not include MS-DOS at all and the recovery console should only be used for recovery purposes (actually, that's all it can be used for as most other operations will fail).
As I said, Windows XP does not include DOS. Earlier versions of Windows (95, 98, ME, etc.) were based on MS-DOS and therefore allowed the user to reboot into DOS mode. THis function no longer exists in XP.
If you want, you can use the NT command line much like the old DOS prompt. To access it, click on your Start
button and click on Run...
In the Run...
box type cmd
and press Enter
Further reading: NT Command Line