might find something like the system's tcpip\pcomos\install.exe which will
not do the thing you want), e.g.
SET MAKESHELL=ash
-SET INSTALL=/wx/wxWindows-2.5.1/install-sh.
+SET INSTALL=/wx/wxWindows-2.5.1/install-sh -c
Be warned that depending on the precise version of your make, the
variable that needs to be set might be MAKE_SHELL instead of MAKESHELL.