You just upgraded to Windows 10 and are experiencing Wifi issues.  The cause of Wifi connectivity issues can be due to various factors.

Common issues people experience are:

Wifi shows limited connection

Wifi disconnects frequently

Here are somethings you can do to help you fix the problem.

Wifi Sharing

Wifi sharing is on by default (unless Microsoft sent updates that made it off by default).  Turn of Wifi sharing, it is ridiculous to have Wifi sharing on a laptop.  We are all familiar to Wifi tethering on Phones,  but if a laptop is already connected to Wifi, chances are you already know the wireless login details and you can just login with your other devices.

Read this article on how to disable the Wifi Sense.

Update Drivers

Visit your computer manufacturers website and search your model so you can download latest updated driver to help fix the issue.  The drivers that come with Windows 10 may not be the best for your Wireless adapter or card inside laptop or desktop.

Upgrade your router

You can also try upgrading your router if you experience slow speeds or lags when you know that your internet is fast enough to handle watching videos or downloading huge files.  Get a Wireless N300 or better router.  The more the wireless router costs the better it is.