"www.dropbox.com refused to connect."

[Fishy]

A classical case of Dropbox website working on every device in network, except a single PC. But, sadly, even with all the support on other similar topics, I couldn't connect to the website.
I have tried using different browsers, turning proxy, antivirus and vpn on and off, using different DNS servers and removing the "hosts" file. So now, when I have tried every other option, I'm trying to reach for support of the community.
My best guess is that the issue persists due to some setting or error in router, but for some reason it works perfectly on any other device.

[Nancy]

Thanks for posting here, @Fishy, and I’m sorry to hear about the issue you’re having. 

As trivial as it may sound, have you also tried to open an incognito window from your main browser? Are you able to sign in to the Dropbox website this way perhaps? 

Also, is there any chance you’ve opened a ticket with our support team? If yes, feel free to send over your ticket number. 

Keep me updated!

[Fishy · Accepted solution]

Thank you for the response, Nancy! Sorry I wasn't able to respond to your messege in time, but here is an explanation.
I resolved the issue about two-three days ago. After countless phone calls and one trip to the office, I was informed by my Internet Provider that they "block some of the unconventional websites"(?). After switching to different company, suddenly, I was able to connect to www.dropbox.com!
I have never encountered this problem with any other website, and the conversations about the issue were a bit strange. But the lesson is simple: don't forget to check the Internet Provider to get information about their policy, or maybe an error on their side.