Answer by user18677603 for How to run a file before setup with Inno Setup

[Code]function PrepareToInstall(var NeedsRestart: Boolean): String;var   ResultCode: integer;begin   ExtractTemporaryFile('卸载.bat');   if Exec(ExpandConstant('{tmp}\卸载.bat'), '', '', SW_SHOW, ewWaitUntilTerminated, ResultCode) then   begin   end   else begin   end;end;

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