"Cant run command"

[rrr@xxxxxxxx (Rene von Rentzell)]

Suddenly, out of the blue, XY3 gives me a "Can't run command"
message when I type DOS on the command line.
Never had this problem before. Everything else seems to work.
Func mem tells me there is 380 k available. What should I do?
TIA

--Rene von Rentzell, Tokyo 
--Nicholas Petreley's First Law of Computer Journalism:
--No technology exists until Microsoft invents it.