Hi!
Based on description you need small, simple, preferrably portable application. What do you think of small 300-400KB(!), no external dependencies, no need in installation, works in win2000,xp,7,8,10 - tested. Just copy and run. No comparison with bloated and slooooow .NET applications.
Program can be done even cheaper when we fully discuss tech task. Sure you will get source codes too so any VB/Delphi/Pascal programmer can upgrade software.
Regards,
Dennis