Check the driver for teh wireless card of the Arcos..and you knwo it works for sure cause you used it in another connection ..than the issue must be on the router ..get into the settings by typing the router's IP address into the browser address bar..and on the wireless settings ..enable the network ..change the channel with a middle one if it is the case and save the settings .For begining I suggest to remove any password for the wireless network to simplify the connection process..Also if you know a hot spot or you have access to another wireless connection try the tablet just to be sure it do nto have issues with the drivers or functionality of the wireless card ..(do not forget to enable the wireless card if it has a button for that )