>I register VFP50.DLL with a setup program, which is created with installation wizard. (I have never problems with hundreds PC95 on network.)
>I try install VFP50 on that NT PC and - under VFP50 my.EXE works fine.
>remark1:
>I try recompile another application (my1.EXE) and it WORKS !
>remark2:
>My1.EXE build on NT works in NT and 95 environment, build in 95 only in 95.
>?

I haven't run into the problems you have with an install created by Setup Wizard; is it possible that your VFP 5 that you compiled and created the Setup had an older copy of the Setup Wizard files? I had some problems a while ago prior to installing VFP 5.0a (build 415) but I don't remeber this as a problem.

When installing a Setup Wizard install under NT, it gets very annoyed if you aren't running as Administrator, or an Adminstrator equivalent, and does jot complete the install. This is because the install may try to update some shared NT components, and it checks for Admin privilege to make sure you have basically Godlike powers to change things, and halts if you don't. There's a quick hack of the STF file (one of the Setup Wizard files that directs the sequence of the install) that will turn off this check. It's OK most of the time to do this; you do have to be a bit more cognizant of possible problems where you install from a user account that doesn't have full privileges in the System32 directory and registry. NB: back up SETUP.STF before you do this in case you screw up or I've not properly explained the change. The hack works like this:

Find SETUP.STF in your Setup directory, and open it with a text editor (Notepad should work fine, or the editor in VFP.) Find the line where the phrase 'DetectAdmin" appears, and note the line number. Then look in the file for a line that contains a "Depends" statement (this is an IF construct used by Setup Wizard) that references the line number you found in the first step. Delete the reference to the number (not the entire line) and save the SETUP.STF you've altered. Your Runtime installer will no longer check for Administrator privileges under NT.