====== Add {app} to path environment variable in registry ======
If your installation contains applications that need to be available from anywhere in Windows, and don't wish to create shortcuts, appending {app} variable value to the Windows PATH variable will do the trick.

Add this to the [Code] section in your script:
For adding {app} to all users path variable
<code pascal>
function NeedsAddPathHKLM(Param: string): boolean;
var
OrigPath: string;
begin
if not RegQueryStringValue(HKEY_LOCAL_MACHINE,
'SYSTEM\CurrentControlSet\Control\Session Manager\Environment',
'Path', OrigPath)
then begin
Result := True;
exit;
end;
// look for the path with leading and trailing semicolon
// Pos() returns 0 if not found
Result := Pos(';' + Param + ';', ';' + OrigPath + ';') = 0;
end;
</code>
For adding {app} to current user path variable
<code pascal>
function NeedsAddPathHKCU(Param: string): boolean;
var
OrigPath: string;
begin
if not RegQueryStringValue(HKEY_CURRENT_USER,
'Environment',
'Path', OrigPath)
then begin
Result := True;
exit;
end;
// look for the path with leading and trailing semicolon
// Pos() returns 0 if not found
Result := Pos(';' + Param + ';', ';' + OrigPath + ';') = 0;
end;
</code>
In order to use the code, add this to the [Registry] section in your script:
<code pascal>
Root: "HKLM"; Subkey: "SYSTEM\CurrentControlSet\Control\Session Manager\Environment"; ValueType: expandsz; ValueName: "Path"; ValueData: "{olddata};{app}"; Check: NeedsAddPath(ExpandConstant('{app}'))
Root: "HKCU"; Subkey: "Environment"; ValueType: expandsz; ValueName: "Path"; ValueData: "{olddata};{app}"; Check: NeedsAddPath1(ExpandConstant('{app}'))
</code>