Windows 10 also classifies the entire Winamp discussion board as malware, and won't let me access it (I'm using my old laptop to post this).
Windows 10 or IE or Edge or could this be your AV (I guess this is called Internet Security suites where they listen in on all your web traffic and sometimes inject own stuff)
If IE/Edge are the problem, just use a real browser. Firefox - or if you're fine with handing all your personal data to Google - Chrome might be worth a try.
If your AV is the problem, switch to something less intrusive like the one included with Windows and use an Adblocker in your browser instead.
I'm giving up on Winamp. What's the next best alternative that has actual readable fonts in a High DPI display, and will run MP3, WAV, PLS, etc?
The new Media Player App of Windows 8+ should be able to handle all of these requirements.
SMPlayer also has a HiDPI mode.
I guess iTunes should scale properly as well. After all Apple was pretty much the first company to include HiDPI in mainstream computers.