I am new to Ubuntu. I have just installed it on my computer and it says that I'm not the owner though there is only one account besides guest.
Also, I previously used Windows 8 and deleted it and all other files on my hard drive with DBAN. Although it says that only 4.4 GB of memory is used but the difference between disk size and free space is more than 30 GB. Why is that? Is that from my previous OS and files?