Hi, i'm using window vista and i don't know how to creat a back up disc by using window vista. can anyone pls.

Certain versions of Vista have a built-in Backup and Restore Center that you can use if you want to backup to an external drive. As far as I know, though, they won't back up files to a CD or DVD. I don't know of any completely free programs that will do that, but you might want to look into something like Backup4All or Handy Backup 6.0.