fallback when no APPDATA is defined

fixes #10616

src/paths.js

@@ -9,7 +9,7 @@ var pkg = require('../package.json');
 
 function getAppDataPath(platform) {
 	switch (platform) {
-		case 'win32': return process.env['APPDATA'];
+		case 'win32': return process.env['APPDATA'] || path.join(process.env['USERPROFILE'], 'AppData', 'Roaming');
 		case 'darwin': return path.join(os.homedir(), 'Library', 'Application Support');
 		case 'linux': return process.env['XDG_CONFIG_HOME'] || path.join(os.homedir(), '.config');
 		default: throw new Error('Platform not supported');