I have switched on mobile hot-spot and turned on Wi-Fi button on the laptop but my network is not detected by my laptop .I was able to access the mobile data through USB but not with hot-spot on--21/2/2019-- i solved the problem,,
Please check with another mobile or tab if you can access the hot spot of the mobile just to make sure there is no issue in the mobile hot spot config.
Do you have connected your laptop with other wifi say your home wifi or something??
Now if you turn on the mobile hot-spot and try to access this network with other device except the laptop and it is not showing in the other device as well then the problem is with the mobile you are hosting the network. Let me assume that the mobile hot-spot is ok and you can access it with other device except the laptop then turn on the wifi first (make sure airplane mode is not on),
1. Go to My Computer Icon> right click> device manager> devices and here under networking drop down check if the wifi device name is showing or not. If not showing then there is definitely some issues with your laptop wifi card.
2. If it is showing here with a yellow triangle then right click on it and select uninstall driver then restart you laptop and again check if yellow triangle is gone or not.
3. Then right click on it again and select check for driver update from windows update (your laptop need to be online).
This should fix your issue otherwise since it is a laptop it will be better to check it in nearest hardware repair shop becs there is a high chance the card is dead.