Have you installed anything from Apple lately like iTunes? If so the Bonjour service that installs with iTunes needs to be disabled and removed.
If not can you check in Device Manager under Network Adaptors and make sure that that Msoft wifi mini port adaptor is disabled, if you can see it there disable it.
If those two problems are ok then there could be a problem with router or your network set up. If it's a router problem the link below will show you how to fix that.
You will need the default gateway of your router for this fix.