move_uploaded_file($upload_file,$store_dir.$pic)
改为
move_uploaded_file($_FILES['file']['tmp_name'], $store_dir.$_FILES['file']['name'])
改为
move_uploaded_file($_FILES['file']['tmp_name'], $store_dir.$_FILES['file']['name'])
你的地址怎么会是c://windows//?????应该是c:\windows\吧?
还有你在$store_dir后面没忘了加"\"吧?