InnoSetup (Pascal): FileExists() doesn't find every file

Question

It seems, that some files which I wanna check with FileExists() can never be found even if they are there, others are found every time. If I put the file "driver.sys" into the "C:\Windows\System32\drivers\" directory, it would never be found (FileExists is false every time i call the function). If I move the file into the Windows root "C:\Windows\" it is found. This doesn't work (while the file is definitely in the folder 'C:\Windows\System32\drivers\'): ``` function isNotDriverInstalled(): Boolean; begin if (FileExists('C:\Windows\System32\drivers\driver.sys')) then begin Log('File exists'); Result := False; end else begin Log('File doesn''t exist'); Result := True; end; end; ``` This works (while the file is in the folder 'C:\Windows\'): ``` function isNotDriverInstalled(): Boolean; begin if (FileExists('C:\Windows\driver.sys')) then begin Log('File exists'); Result := False; end else begin Log('File doesn''t exist'); Result := True; end; end; ``` Btw: I am using Windows 7, 64 Bit.…

Accepted Answer

Your `System32` directory is mapped to the `SysNative` path due to `File System Redirector`, so as you can see, hardcoding of such directory path is not that easy. Better use one of built-in constants listed below:

1. The {sys} constant:

You can use the `{sys}` constant, but make sure you allowed the setup to run in 64-bit mode. For more information about how to do it, see the `ArchitecturesInstallIn64BitMode` directive reference and be sure to read the `64-bit Installation Limitations` topic.

From the `{sys}` constant reference:

The system's System32 directory. For example: If you used {sys}\CTL3D32.DLL on an entry and the system's Windows System directory is "C:\WINDOWS\SYSTEM", Setup or Uninstall will translate it to "C:\WINDOWS\SYSTEM\CTL3D32.DLL".

On 64-bit Windows, by default, the System32 path returned by this constant maps to the directory containing 32-bit system files, just like on 32-bit Windows. (This can be overridden by enabling 64-bit mode.)

Here is how you can use it:

```
if FileExists(ExpandConstant('{sys}\drivers\driver.sys')) then
  Log('File exists');
```

2. The {syswow64} constant:

From the `{syswow64}` constant reference:

On 64-bit Windows, the system's SysWOW64 directory, typically "C:\WINDOWS\SysWOW64". This is the actual directory in which 32-bit system files reside. On 32-bit Windows, 32-bit system files reside in "System32" or "System", not in a separate SysWOW64 directory, so this constant will resolve to the same directory as {sys} if used there.

Do not use this constant unless you have a specific need to obtain the name of the actual directory in which 32-bit system files reside. Gratuitously using {syswow64} in places where {sys} will suffice may cause problems. (See the documentation for the [Files] section's sharedfile flag for one example.)

Here is how you can use it:

```
if FileExists(ExpandConstant('{syswow64}\drivers\driver.sys')) then
  Log('File exists');
```

InnoSetup (Pascal): FileExists() doesn't find every file

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