How do I reinstall or troubleshoot my wifi software?

How do I reinstall or troubleshoot my wifi software?
I'm running Yosemite on my mid 2010 Macbook Pro and I've been having issues with my wifi software. When I boot up my machine, the wifi seems to work perfectly for about a minute or two showing all available wifi networks. Then the wifi turns off automatically and won't turn back on. Occasionally when I hover my curser over the blank wifi logo in the title bar and there's a warning shown under it that says "No wifi software installed". Then after next boot up the same... works then turns off. It was working for a longer interval after boot up about a month ago after I upgraded to Yosemite. Any solutions?

This is odd, I have seen a "No WiFi Hardware installed" message before which usually refers to a faulty Airport card. However you might like to try Network Preferences under the WiFi icon just to see if the WiFi network is visible in the sidebar. Have you tried turning WiFi off and on again, when was the last time you rebooted the Macbook?