add error handling to windows install branch

installer.py

@@ -173,7 +173,15 @@ if platform.system() == "Linux":
 elif platform.system() == "Windows":
     print("Operating system detected: Windows")
 
-    os.chdir("AppData/Roaming/.minecraft")
+    try:
+        os.chdir("AppData/Roaming/.minecraft")
+    except:
+        print("[ERR!] Fatal: Minecraft directory not found. (Is Minecraft installed?)")
+        print("[ERR!] Fatal: This window will close in 10 seconds.")
+        print
+        time.sleep(10)
+        pass
+    
     mcfolder = str(Path.cwd())
     print("[INFO]: Changed current working directory to '" + str(mcfolder) + "'")