Weird Problem

[Jokniserous]

So, first off I have an ARRIS network.
I usually connect: A Desktop Computer (Win 7), A laptop (Win 10), a tablet (Android) and two smartphones (Android both).

Starting like 3 days ago, whenever I connect my laptop to my wireless network the whole network freezes.  Every device previously connected to the network gets disconnected and nothing works, neither does the laptop.  What i usually do to fix this is I first disconnect the laptop, then i reset my router-modem and wait for everything to re-connect.  This is obviously a tiring process and I can't connect my laptop to the internet ;(.  The only error message i've ever gotten (and I think this is the problem) is 'Another device on this network has the same IP Address' and i don't know how to fix this.

I've also tried using wired, but that somehow doesn't work either.  Oh and 1 more thing, whenever I connect my laptop, the modem's lights go flashing like crazy.

Thanks in advance for any help I might receive.  Hopefully this is fixable. 
Jokniserous

[Mark.]

from that error message, you have more than one device on your network with the same IP address - never good.

log onto your modem configuration page and check it is setup to act as a DHCP server - that is, automatically assign IP's to new devices.
then on the laptop, go to Control Panel, (change View by: to small icons) Network and Sharing Centre, Change Adapter settings, double click your Ethernet Adapter, Properties, double click Internet Protocol Version 4, tick the top Obtain an IP address automatically and the lower Obtain DNS Server automatically options.

Restart (not reset) your modem and wait for all the usual lights to connect.
Reboot all your connected devices, as each starts the modem will locate an unique IP to each.