Visual Basic Folder rename under WinNT

I want to accomplish the following under WinNt4.0 using VB5.0

if exist c:\GPD5 then
begin
rename c:\malo GPD2
rename c:\GPD5 malo

call c:\malo\<database application X>
make current dir c:\malo

goto end
end;

if exist c:\GPD2 then
begin
rename c:\malo GPD5
rename c:\GPD2 malo

call c:\malo\<database application X>
make current dir c:\malo

goto end
end;

call c:\malo\<database application>

end:
echo you are about to launch application X


This program when written in VB5.0 works under window95 and 98, However, a run time error occurs when
this same program is used under WinNt 4.0. Why? and if possible can you help me. Please send advise to
[email protected].

Thank you.