To switch your DOS applications between "Full Screen" and "Windowed" mode under Windows NT command shell, press ALT + ENTER . Each time you depress ALT+ENTER the DOS application will switch modes. If you have an old 16-bit DOS or Win3.x application that runs too slow, try full-screen mode. If the application is still too slow, try disabling the Compatible Timer Hardware feature in the _DEFAULT.PIF or the application's PIF under the NT-specific section of PIF Editor. If the application pauses occasionally, disable Idle Detection in the Advance section of the application's PIF. If the DOS application can be configured for printing, choose LPT1, LPT2 over parallel port. Most DOS apps use Int17 to print when configured for LPTx.