I don`t have that folder. The only place where cannabis exist is C:/program files/cannabiscoin. And there is three files there:
cannabiscoin-qt(app file) ; copying(txt file) ; uninstall.
Should i put this "dat" file in this folder?
The first time you run the wallet the appdata>roaming>cannabiscoin folder will be created.
Is it possible that you have those folders hidden(not visible)? By default windows keeps these folders hidden.
Also, your wallet file should be named wallet.dat not cann.dat.