hard drive issue!!!

well heres my issue i had a hp pavillion laptop which stopped working after my daughter dropped it. I took out the hard drive so i could get all our pictures and video files off of it so i bought a usb enclosure which seems to work fine it powers on and i can see all the user accounts but i cant access them when i try it says access denied. there was a password on it when it was running on the laptop how do i gain access to these files? thank you ahead of time!!!!!!