diff --git a/lib/registry.js b/lib/registry.js
index 6319ae3..bcae480 100644
--- a/lib/registry.js
+++ b/lib/registry.js
@@ -140,7 +140,7 @@ function pushArch(args, arch) {
  * Implemented only for Windows
  */
 function getRegExePath() {
-    if (process.platform === 'win32') {
+    if (process.platform === 'win32' && process.env.windir !== undefined) {
         return path.join(process.env.windir, 'system32', 'reg.exe');
     } else {
         return "REG";