.net - C# Application not running on windows 7 -

i have made application c# targeted .net framework 4.5.2. i've made visual studio 2015.

i have tested , works fine on win 10/8.1/8. on windows 7, stops working right away, doesn't show form.

i have installed .net framework 4.5.2, didn't work. i've installed vcredist 2017 both 64 , 32bit, still didn't work. installed .net framework 4.6.2, didn't work either.

i haven't used special in except ionic.zip.dll , docotic.pdf.dll, both of not called @ startup, not issue.

i tested version of app doesn't have in it, still stopped working error right away.

so, there i'm missing? should install i'm forgetting?

note: have tested on 2 different systems windows 7, , both gamers, have of latest version of drivers , stuff installed. have no idea absence of causing issue.

any appreciated.

update: installed windows 7 32bit on pc on virtual machine , installed net framework 4.5.2 , app worked. why not working on other windows 7s?

another note: other windows 7s tested app on 64bit. windows 10 64bit , works, win 8 , 8.1 tested app on. doubt issue, thought mentioning might help.

update2: app doesn't throw , exception, gives stopped working error event name being "clr20r3".

if application stops working kind of exception. in case while loading application. there 2 possibilities see:

1. your application special in entry point (before creating main form) or in other thread created in entry point or in main form constructor.
2. you're missing dlls.

what should do: check first point - if i'm right, debug other thread. if isn't case download dependencywalker. application shows dlls application depends on. what's more, shows dlls missing in system.

just open exe file in dependency walker , you'll see.