@MikkelDK 

If you haven't given up yet on troubleshooting your laptop, I can offer some suggestions, but I'd rather see it done in more methodical way. As I read this forum conversation, it is not clear for me what is your network configuration, what is your Deco mesh configuration and what changes have you made to your Deco mesh and home network while trying to fix the slow download speed on laptop.

Let's clarify that first.

1. What configuration changes, if any, have you made in your ISP router when you deployed Deco M5 mesh in your house?

2. Do you run your Deco mesh in Router or in Access Point mode?

3. Do you have 2.4GHz enabled for Main Network, under WiFi settings of Deco app? Do you have 5GHz enabled there?

4. Do you have Guest network enabled (same place, WiFi settings of Deco app), and if yes, same question as above for 2.4GHz and 5GHz.

5. You have run "Test Internet Speed" from Deco app and saw 900Mbps Download speed, is this correct? If yes, what is upload speed reported there?

@Alexandre. Hello, please see answers below:

1. I have made no changes to my ISP router, pretty much just plugged in the cable between the router and the main deco unit

2. I run my Deco in "Router" mode, I tried access point mode, but didnt get any internet, i suspect i have to get my ISP provider to unlock the router in order for this to work OR use my old TP link router between my ISP router and the Deco access point 

3. I have disables the 2.4 network, which helped a bit with the download speed

4. I do not have Guest network enabled

5. Yes download speed of around 900 mbps and upload of 500 mbps when testing through the Deco app

Hope this helps 

@MikkelDK 

OK, so if I understand it correctly, ISP provided you with the modem and you used TP-Link router attached to it. Now you have removed TP-Link router and connected Main Deco to the modem.

In this configuration, the only WiFi signal provided in your house should be from Deco mesh.

Just to confirm, your laptop at your home can connect to only Deco mesh WiFi and not to any other WiFi network, right?

Assuming you still have 2.4GHz disabled (and disable it if not), please do the following:

1. Power off both Satellite Deco nodes, leaving just Main Deco running

2. Bring laptop to Main Deco and position it about 6ft from it, in plain view. Connect laptop to power outlet, don't run it on battery for this test

3. To make clean test, turn off/on WiFi on laptop or just reboot laptop

4. Open web site fast.com in browser on laptop, and when it stops running speed test, tell what download speed it reports

5. You must have smartphone to manage Deco mesh, please bring it to Main Deco, too, and open fast.com in browser on smartphone. What download speed it reports?

@Alexandre. Hello, yes the setup you mentioned below is correct and my laptop can only connect to the Deco network.

I followed your steps by disabling other Decos and disabling 2,4 ghz and moved approx 6 feet away form main deco and got the following speeds:

- Laptop: 420 mbps

- iphone 12 browser speed test: 420 mbps

- Deco app speed test: 910 mbps

Does that make sense to you?

@MikkelDK 

Seems a bit low for 5GHz, and is max speed for 2.4GHz. You are sure you disabled 2.4GHz, right?

At least, you have consistent smartphone and laptop speed test at this point, with Main Deco.

There are two possible ways to see if Main Deco speed can be better:

1. Bring back TP-Link router, turn off its WiFi, attach Main Deco to it, change Operating Mode to Access Point, run test again. 

or

2. See Using QoS feature of Deco TP-Link article and up QoS setting to 1000 Mbps.

It is more effort, but bringing back TP-Link router (option 1) is what I would prefer - it is necessary to establish absolute best speed Deco M5 can deliver. 

@Alexandre. Ok thanks. Do you know how to disable wifi on a standard tp link router, is it bridge mode? And do i have to reset main deco and satelites and make a new network when changing to access point mode?

@MikkelDK 

You do not need to switch TP-Link router to bridge mode. Login to its Web admin interface, find where WiFi settings are, turn off WiFi network there. You only need to turn WiFi signal off in TP-Link router.

You do not need to redo or reset Deco mesh. Just connect Main Deco to one of TP-Link network ports, and when Deco is up, switch its Operation Mode to Access Point, in Deco app.

After you've done that, your network will be managed by TP-Link router (IP addresses allocation, firewall rules, etc.) as it were before Deco, and Deco mesh will just provide WiFi signal.

By specs, M5 should deliver up to 400Mbps on 2.4GHz and 860Mbps on 5GHz. I would have expected speedtest for laptop and for smartphone connected to Main Deco wirelessly and in close proximity to it to report download speed in excess of 500-600Mbps.

@Alexandre. Ok thanks so much for your help, i found the wifi setting. Just last question before trying it, will the ssid be the old tp link one or the new Deco network i made...?

@MikkelDK 

If you turn WiFi signal off in TP-Link router, the only SSID your devices (laptop, smartphone) should see is the new Deco SSID. 

In case your devices see old TP-Link router SSID - you haven't turned TP-Link router WiFi signal off.

@Alexandre. Ok, so now i connected to the old router and disabled wifi on that one and changed Deco to AP mode....and when i test now i get download speed anywhere from 420-560 mbps...I guess there is not much else to do....?