I've tried in many browsers, but I don't get what happens. Every browser my download is slow. However, on Steam, my download is 100% normal. I've used fast.com (powered by NETFLIX) to test my speed and it's still high.
@jori If the problem happens with all browsers, then probably this may not be the best place to ask for help. A more generic Windows forum could be better.
Is VPN on by chance? Did you already tried disabling your antivirus or any related software?
@leocg My VPN is off and antivirus on. However, on Google Chrome it wasn't always that I had this issue, sometimes it downloaded normally. Here on Opera is always slow. But I'll try going to a Windows forum, then. Thanks for the help