My laptop connects to internet but doesn't work but my mobile does

when i connect my ASUS laptop to internet it works but after 3 mins it will stop working and i have to turn off and on my modem but i have no problem connecting and using internet via my mobile or ASUS tablet.

i really need to fix this please someone help me. also i tried restarting my computer or turning off and on my modem or trouble shooting the wifi but is says nothing.

so i need a new answer. please someone help.