Wesley said:
Win Key + R | type: cmd | ENTER
Or find Command Prompt in All Programs - Accessories.
Note that this is not true 16 bit DOS but an emulation - under which a
lot of DOS programs will run, but not all. In particular anything
needing a resident driver or TSR, or which tries to handle hardware
direct is a non-no. Those need running from a True DOS: which means
booting a startup floppy