Windows may be set to a "Balanced" power setting, which will affect the performance of your Wi-Fi card by placing it to power-saving mode.
The High-Performance power plan disables dynamic scaling of performance to match the workload and instead delivers constant high-performance levels at the cost of increased power consumption. This power plan is useful in certain scenarios that are highly performance or latency sensitive or in scenarios in which power consumption is not an issue.
1: Right-click the battery icon in your system tray and choose “Power Options”
2: From here, you can select your power plan. The plan you need to select is “High Performance” but it may be hidden. If it is hidden click on the “Show additional plans” heading at the bottom.
3: Select "High Performance" and close the window.