How to fix slow WiFi speed on windows when it is fast on phone

Hello, thank you for reaching out to Microsoft Q&A.

Make sure your PC is close to the Wi-Fi router. A weak signal can lead to significant drops in Wi-Fi connectivity and speed.

Also, may I please know if your Router supports 5GHZ network or not? You can reach out to the ISP or check the router's IP address and wireless settings for 5GHz band options. If the router supports 5GHZ, check if your Windows 11 PC supports 5GHZ bandwidth.

Open CMD (Admin) window, run the command below.

netsh wlan show drivers

If you see 802.11a" or "802.11ac" or "802.11ax" in the list, your WiFi adapter supports 5GHz.

1. Go to Device Manager > Expand the arrow next to Network adapters.
2. Right-click your default Wi-Fi network driver (Intel or Realtek) > Select Properties > Advanced tab > Set it to Dual band 802.11 a/b/g wireless mode.

You can also update your network drivers from your PC manufacturer's website and see if there are any changes to your network speed.

Let me know if you still need more help.