Windows Caching Programs

What I found out is that windows makes a copy of programs and data
files for faster loading and places them in this PreFetch folder. I
was unable to verify but this is the possible cause of the problem.
Windows may have just thought that the .exe had not changed and did
not re-download it from the server.

Due to not being able to reproduce the issue, I guess this is as far
as I can go.

Thanks for all your help.