>some time back, i created a visual foxpro application containing a tree control (activeX) that requires file comctl32.ocx to be in the windows\system directory. no problem. later i installed visual basic. the same file existed with basic and overwrote foxpros comctl32.ocx file. my foxpro app no longer worked properly. i had to copy foxpros own comctl32.ocx file back. if i had written an app in both foxpro and basic that ended up on the same computer, how could this conflict been resolved?

You must use the same version of comctl32.ocx in both applications. To do this registry the newest version, and rewrite the forms based on this activex. You can first copy the methods to not rewrite at all.
Carlos.