Unable to login to Admin panel – Xampp Local Site

hi guys ,

I googled and followed instructions to setup a copy of live website onto localhost using Xampp. Everything looks good , I can open my test site but can not access wp-admin page , everytime I put in username and p/w it loops me back to same page without any message or warning , If I put in wrong username or p/w , I do get an error message about incorrect username p/w

I have already replaced siteurl and home page to localhost site address , what else have i missed ??

Thanks in adv .