Do not have permission to update BIOS on XPS 15z

Hi I'm new here and having a very frustrating time trying to update BIOS on my Dell XPS 15z. I don't have a warranty anymore, so coming here is about all I know left to do. 

Last night, the power light started flashing orange and white, and it isn't charging (It says 92% available, plugged in but not charging). The last time it did this, I was able to talk to someone online, and they updated my BIOS remotely. This fixed the problem, and it's been fine up until now.The laptop is a little over a year old, so I wouldn't think the battery would be dead. In any case, I'd like to update BIOS first to see if that would fix the problem without having to go out and buy a new battery. 

The BIOS right now is A05. I downloaded A11, but when I tried opening the file it said I didn't have permission to, even when I tried running it as an administrator. The same happened when I tried A06. The files were downloaded to the Desktop using the Dell Download Manager as well as a single download (I've tried multiple times). I tried getting into the BIOS screen from startup, but it didn't help (all I was really able to do was change date and time, and I could view the BIOS version. Is that the right screen? I got there using F2). 

I don't know what to do, and I am getting VERY frustrated. I've tried looking elsewhere, but it hasn't helped at all. I would very much appreciate any help...