>I have an application which uses the following
>
>oXLS = thisform.OleControl1.object.document
>oExcel = oXLS.Application
>
>it runs on one machine within my client's set up but not on others
>
>what software needs to be installed in order to run on every machine

Don't put the activex control on your form. Instantiate it like this:

oExcel=CREATEOBJECT("Excel.Application")
IF VARTYPE(oExcel)<>"O"
	** not working
	RETURN
ENDIF