@merajsyed
Mention wifi router model/number.
Connect rj45 to WAn /Internet port of wifi router
Select YES "ISP requires userid PW?"
Connect another Rj45 from lan1 to desktop.
Choose Ip address DNS all automatically select.
( or from (2) below.)
WIfi as usual.
Feedback. with screen shot of Connection status .
2.
In computer Desktop
Start RUn type cmd Ok
New window
type ipconfig /all
Check Data for lan .. Use max details in WIFI router.
copy/paste data here. ( ONLY LAN DATA )
3.
Confirm OS used Windows 7/XPSp3/Vista/ etc.
Feedback.