You can try turning off your firewall software, since this is a common issue for losing wireless connection. After turning the firewall off, visit a trusted site and see if that was the cause. Make sure to turn your firewall back on soon to keep your computer secure. You can also try to reset your router.
If you’ve upgraded Windows recently, that could be the cause of your wireless connection failure. Your current adapter might be tailored to your last Windows version, not your upgraded Windows version. You may need to get an upgraded adapter for your current version of Windows.