WinNT 3.51 detection by default setup (from NT4 and up)

Hello,
with a default setup with Version plugin, if I use in the .onInit function the following code:

Function .onInit
Version::isWindowsNT351
Pop $0
StrCmp $0 "0" +3
MessageBox ...
Abort
FunctionEnd

Do I get the message box, if the os is Windows NT 3.51, or not ?
That is, do I get the message box before the setup stops because the deafult setup is normally set for Win NT 4 ?

Windows NT 3.51 is not supported by NSIS. Installers won't even start on it.

Assuming it did, with your script, it'd show the message box and quit, if the installer isn't running on NT 3.51.

Then, is the message shown SURELY on Windows NT 3.51 ?

Yes. It will skip the message box, if it's not running on NT 3.51. Again, assuming NT 3.51 is supported, which is not the case.

You should use the LogicLib for clearer scripts.