Notebook is not connected with wifi modem not showing wifi lights?

Hi all i have old asus laptop which i just started using everything is fine os,display,ports etc . But wireless wifi not getting connected also not showing lights i tried to connect with ethernet cable got connected with that. But i am not sure which wireless adapter cards and from where drivers are need to be installed and what are the options i can apply ? I think my brother have updated os may be drivers are missing . On asus website i tried to find out but my model number not showing there as its old. Please help i think hardware is fine but software, or drivers are damaged . Can anyone help.?