need help to attach database?

I am trying to attach database but did not go through, need to fix this issue?

CREATE DATABASE AdventureWorks2012
ON (FILENAME = 'C:\Users\arjun\Downloads\AdventureWorksDW2012_Data.mdf')
FOR ATTACH_REBUILD_LOG ;

Error

Msg 5133, Level 16, State 1, Line 1
Directory lookup for the file "C:\Users\arjun\Downloads\AdventureWorksDW2012_Data.mdf" failed with the operating system error 5(Access is denied.).