TI 2016 - How to remove NAS User (Network User-Pass)?

Hi,

I tried to backup my Win7 x64 HTPC to a Network-Drive which is hosted on my NAS. TI2016 asked for a User and Pass (I was wondering because its a SMB Share on Windows 7 with a drive letter) but okay I typed in the NAS User and Pass for this SMB Share - after I did I noticed that it was the wrong user because I have a seperate User for my HTPC with different rights - but I can't find any setting where I can do this.

Maybe I can fix it when I change the Password of the logged in User - but there must be a easier way??

Thanks in advance!