Argueta42
I've been going over the previous posts about your problem and the solutions suggested so far. And I am just as stumped as you are, so much so that I am starting to think that your equipment may have a fault somewhere.
However, you said that you have a laptop and a desktop, from this I presume that your desktop is connected via a patch cable to the modem and your laptop is connected wirelessly.
OK, if I am right then I would suggest that you check your desktop "port forwarding" configuration again, because I have recently found that when I upgraded my LW Pro to V4.18.4 my port forwarding settings no longer worked.
What seem to have happened was that my original PF settings were changed by my modem, my PC's name was converted to an IP address, and this would not work for V4.18.4. So when I changed the modem's allocated IP address back to my computer's name LW Pro 4.18.4 started to work and has been working ever since.
If this works for your desktop then apply the same solution to your laptop and if that works as well then add the TweakMaster utility as well:
TweakMASTER - The Supreme Internet Optimizer
It can help in maintaining your wireless connection (my son uses this to strengthen his wireless connection to my modem).
UK Bob