Fix inno setup paths cloudfuse (#294)

* Only change system path to add cloudfuse

* Fix issue

build/windows_installer_build.iss

@@ -34,6 +34,8 @@ ArchitecturesInstallIn64BitMode=x64
 SignTool=signtool /d $q{#MyAppName} v{#MyAppVersion}$q $f
 SignedUninstaller=yes
 VersionInfoVersion={#MyAppVersion}
+; Tell Windows Explorer to reload the environment
+ChangesEnvironment=yes
 
 [Languages]
 Name: "english"; MessagesFile: "compiler:Default.isl"
@@ -69,10 +71,31 @@ Source: "..\winfsp-2.0.23075.msi"; DestDir: "{app}"; Flags: ignoreversion
 Name: "{autoprograms}\{#MyAppName}"; Filename: "{app}\{#MyAppExeName}"
 Name: "{autodesktop}\{#MyAppName}"; Filename: "{app}\{#MyAppExeName}"; Tasks: desktopicon
 
+[Registry]
+Root: HKLM; Subkey: "SYSTEM\CurrentControlSet\Control\Session Manager\Environment"; \
+    ValueType: expandsz; ValueName: "Path"; ValueData: "{olddata};{app}"; \
+    Check: NeedsAddPath('{app}')
+
 [Run]
 Filename: "{app}\{#MyAppExeName}"; Description: "{cm:LaunchProgram,{#StringChange(MyAppName, '&', '&&')}}"; Flags: nowait postinstall skipifsilent
 
 [Code]
+function NeedsAddPath(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;
+
 var
   ResultCode: Integer;
 
@@ -92,12 +115,6 @@ begin
       end;
     end;
 
-    // Add cloudfuse to the path
-    if not Exec('cmd.exe', '/C SETX PATH "%PATH%;' + ExpandConstant('{app}') +'"', '', SW_HIDE, ewWaitUntilTerminated, ResultCode) then
-    begin
-      MsgBox('Failed to update PATH. You may need to add the path manually to use Cloudfuse on the command line.', mbError, MB_OK);
-    end;
-
     // Install the Cloudfuse Startup Tool
     if not Exec(ExpandConstant('{app}\{#MyAppExeCLIName}'), 'service install', '', SW_HIDE, ewWaitUntilTerminated, ResultCode) then
     begin