I can't find the previous thread you referred to. (Perhaps you tagged your question onto someone else's thread). However, if you're having problems getting a laptop to connect wirelessly to a router, the very first thing to do is to reset the TCP/IP stack.
If you've not done that yet, here's how to do it. (I'm assuming that you've got Windows 10, as you've mentioned it previously):
Go Start > All Apps > Windows System
RIGHT-click on Command Prompt.
Select Run As Administrator
Type 'netsh winsock rest' (without the quote marks)
Press Enter
Type 'netsh int ip reset' (again without the quote marks)
Press Enter
You'll see various messages, including some (e.g. 'Access Denied') which might suggest that it's not worked but the important bit has been done.
Restart your laptop and see if things have improved.
If that doesn't work, the next thing to try is changing the channel on your router:
To do that, open any web browser.
Type 192.168.1.25 into the address bar and hit Enter.
Enter the username and password for your router. (The username will be 'admin'. The password is on sticker on the bottom of your router; it will look like 'CPYYWWPPXXX' and is case-sensitive).
Click 'Home Network' on the left-hand menu.
Under 'Wireless', click 'WLAN: PlusnetWireless'
Click 'Configure'
Click 'Details'
That will show you the current settings for your router. From there you should find an option to select a different channel.
If the 'techie' who advised you to change your router didn't suggest the above he's got no right to call himself a 'techie'!