Internet Speed on Windows BootCamp Partition Incredibly Slow

Hello,

I have a 15" 2015 Retina MBP which I have had since July 2015. After purchasing the MBP, I installed Windows 8.1 via BootCamp. After installing it, everything worked fine with no issues up until two days ago.

Two days ago, I turned on my MBP and booted into Windows. I then began to notice that my Internet was incredibly slow. I ran a speedtest and found that my download speed was only 0.1MB/s, much lower than the normal 10MB/s.

Later, I booted into OS X to check to see its Internet speed and found that it was at the normal 10MB/s. Since then, I have tried numerous things to try and fix the slow Internet on my Boot Camp partition, but none have been helpful at all. These changes have included:

• Disabling any power saving features for the Broadcom wireless adapter.
• Using a wired Ethernet connection.
• Setting up a different router.
• Making various changes to the Windows registry, such as those mentioned in this post.
• Resetting the System Management Controller (SMC) on my Mac.
• Resetting the NVRAM on my Mac.
• Doing a factory restore of Windows 8.1.
• Upgrading Windows 8.1 to Windows 10.
• Deleting the entire Boot Camp partition and doing a completely fresh install of Windows 8.1.

None of the above has had any impact on the now maddeningly slow Internet speeds in my Windows Boot Camp partition. What is so confusing and frustrating is that everything had been fine for 6-months+ and now all of a sudden out of nowhere, the Internet in Boot Camp has essentially stopped working.

It's clearly not a hardware problem with the MBP as the Internet works fine on OS X. And it's also hard to figure out how it could be caused by a specific setting in Windows since I have tried various fresh installs of Windows.

I will also note that when I access my BootCamp partition via VMWare Fusion, the Internet speed is fine since it bridges the Internet connection from OS X to Windows.

Any help on how to fix this would be deeply and greatly appreciated. I have spent the past two days exhausting every possible solution I could think of and have found nothing that works.

Thanks.