1. Hold or press Windows key + R to open command prompt and type 'gpedit.msc' w/o single quote.
2. Now double click the Computer Configuration as per screenshot.
3. Now double click Administrative Templates.
4. Double click Network.
5. Double click QoS Packet Scheduler.
6. Double click Limit reservable bandwidth.
7. First click on Enabled.
Then change Bandwidth limit (%) to zero. As per screenshot.
Then click OK.
After you click OK, you have now cut the part of windows bandwidth. There is no reserved bandwidth now. You will experience a difference that your internet speed is optimized now.