What's Wrong?
Function .onInit
IfFileExists "$INSTDIR\conf.dat" exit
exit:
MessageBox MB_ICONINFORMATION|MB_OK "A previous version is installed"
Abort
FunctionEnd
Archive: What's Wrong?
What's Wrong?
Function .onInit
IfFileExists "$INSTDIR\conf.dat" exit
exit:
MessageBox MB_ICONINFORMATION|MB_OK "A previous version is installed"
Abort
FunctionEnd
You must jump somewhere else if the file doesn't exist. Use the LogicLib for simpler code:
!include LogicLib.nsh
Function .onInit
${If} ${FileExists} $INSTDIR\conf.dat
MessageBox MB_OK "exists..."
Abort
${EndIf}
FunctionEnd
And for future posts, please at least include what exactly doesn't work as it should for you, instead of letting people guess.