diff --git a/clang/lib/Driver/WindowsToolChain.cpp b/clang/lib/Driver/WindowsToolChain.cpp
index ad84d02f5981..db36f1eba713 100644
--- a/clang/lib/Driver/WindowsToolChain.cpp
+++ b/clang/lib/Driver/WindowsToolChain.cpp
@@ -146,30 +146,29 @@ static bool getSystemRegistryString(const char *keyPath, const char *valueName,
         char numBuf[32];
         strncpy(numBuf, sp, sizeof(numBuf) - 1);
         numBuf[sizeof(numBuf) - 1] = '\0';
-        double value = strtod(numBuf, NULL);
-        if (value > bestValue) {
-          bestIndex = (int)index;
-          bestValue = value;
+        double dvalue = strtod(numBuf, NULL);
+        if (dvalue > bestValue) {
+          // Test that InstallDir is indeed there before keeping this index.
+          // Open the chosen key path remainder.
           strcpy(bestName, keyName);
+          // Append rest of key.
+          strncat(bestName, nextKey, sizeof(bestName) - 1);
+          bestName[sizeof(bestName) - 1] = '\0';
+          lResult = RegOpenKeyEx(hTopKey, bestName, 0,
+                                 KEY_READ | KEY_WOW64_32KEY, &hKey);
+          if (lResult == ERROR_SUCCESS) {
+            lResult = RegQueryValueEx(hKey, valueName, NULL, &valueType,
+              (LPBYTE)value, &valueSize);
+            if (lResult == ERROR_SUCCESS) {
+              bestIndex = (int)index;
+              bestValue = dvalue;
+              returnValue = true;
+            }
+            RegCloseKey(hKey);
+          }
         }
         size = sizeof(keyName) - 1;
       }
-      // If we found the highest versioned key, open the key and get the value.
-      if (bestIndex != -1) {
-        // Append rest of key.
-        strncat(bestName, nextKey, sizeof(bestName) - 1);
-        bestName[sizeof(bestName) - 1] = '\0';
-        // Open the chosen key path remainder.
-        lResult = RegOpenKeyEx(hTopKey, bestName, 0, KEY_READ | KEY_WOW64_32KEY,
-                               &hKey);
-        if (lResult == ERROR_SUCCESS) {
-          lResult = RegQueryValueEx(hKey, valueName, NULL, &valueType,
-            (LPBYTE)value, &valueSize);
-          if (lResult == ERROR_SUCCESS)
-            returnValue = true;
-          RegCloseKey(hKey);
-        }
-      }
       RegCloseKey(hTopKey);
     }
   } else {