I suggest you ask the perlIDE site this question. PerlIDE is a sourceforge project and is not directly connected with Perl itself (so far as I know).

You may be confused by your use of the term "dos mode". I suspect that what you mean is "Console mode". The black window displayed when you run Perl on Windows is called a Console, since Perl is a Console application. It has nothing to do with DOS other than the fact that one black window looks much the same as any other.

If you are using a graphics only application there are ways of supressing the console based on the Win32 API FreeConsole. I suggest you SuperSearch on that if that is what you need.