after i join my friends game.. after putting password it shows connection error ..what should i do??

hi
explain exactly what you did and what you have done to fix it.
if you have the steam version follow this turorial for a good install: https://support.voobly.com/display/vkb/KB1054+Clean+installation+of+Aoe2HD+with+compatibility+patch
you need to make sure your pc firewall allows voobly and the game through.