Passing an installed file (.reg) to program (regedit) in Inno Setup fails with "Cannot import ... Error opening the file"

Question

I would like to import a reg file after installing. Here is my code:

procedure CurStepChanged(CurStep: TSetupStep);
Var
    ResultCode: Integer;
begin
    if CurStep = ssPostInstall then begin
        Exec('{win}\regedit.exe', '{app}\MyReg.reg', '', SW_SHOW, ewWaitUntilTerminated, ResultCode);
    end;
end;

I also tried this:

[Run]
Filename "{win}\regedit.exe"; Parameters: "{app}\MyReg.reg";

Both fail with:

Cannot import MyReg.reg: Error opening the file. There may be a disk or file system error.

I tried to import reg file manually (cmd.exe)

C:\Windows\regedit.exe MyReg.reg

Answer 1

If you are installing to Program Files, then the {app} contains spaces.

You should always wrap paths to double quotes to allow paths with spaces.

Exec('{win}\regedit.exe', '"{app}\MyReg.reg"', '', SW_SHOW, ewWaitUntilTerminated, ResultCode);

Similarly:

[Run]
Filename "{win}\regedit.exe"; Parameters: """{app}\MyReg.reg""";