No Administrator Privileges on WIN7 PC: Unable to Modify, Download or Delete Files in C: Drive

Hi. I have been struggling for several hours with an annoying problem.
I can't download any file to the C: drive (where I have the system) every time I download something, I get this message:
"You do not have permission to modify files in this network location"
Everything was OK a few hours ago. Now, even if I want to delete a file from the desktop, I have to "confirm" it with administrator privileges and only then it is removed, the problem is that I am the only user of the computer and I am the main administrator on it, so I should have such privileges in advance.

I have already used this advice, but nothing helped
http://softonet.pl/publikacje/poradniki/Jak.u...radnik.dla.uzytkownikow.systemu.Windows,735/2

This also doesn't help:
"In the start menu, type cmd, click PPM and run as administrator, and enter the command: net user administrator / active: yes"
I have WIN7

Give yourself full read and write access to C: \ and subdirectories.

You can also try to create a new account with administrator privileges and check if the read / write permissions are ok on this account.

Okay, it's fixed.
Oddly enough, I created an administrator account on my computer as an administrator, and mine was replaced as "secondary" with administrator privileges, which did not work properly.

Problem solved. Thank you for your help