Network/MikroTik solve problem of internet access

i have a network as in image bellow. as you see desktop computers are connected to switch by cables and have their own network of 172.xxx. and they access internet via ip [login to view URL] (image attached for network card of desktop) internet access for guests (handhelds/laptops,etc) are through wifi on [login to view URL] i have a problem: - many times i loose internet connection on the wifi (desktops though have internet access) - sometimes desktops and wifi users loose internet access (though there is internet) - when there are many users... the above happens a lot.. as if packets gets lost or something in the inside network i have to restart zyxel gateway and router for things to come back.. many times it takes time for computers/wifi users to be able to use internet (have to switch on/off many times) one thing though i notice.. in all the problems above .. always always the computer with ip [login to view URL] has internet when the access to internet by desktops and/or wifi goes out. This computer has on it the Mikrotik router software (winbox) I need to solve problem A question that might solve Can i remove the ZyXel gateway and have things connected to router directly... then router will give wifi users DHCP on 172 network?