Look through any recent windows updates to see if around the same time an update was installed, this problem occurred: Windows Update - View Update History Details
Did anything get installed or an application update recently? Don't forget to check your antivirus for recent updates. Some 3rd party antivirus softwares can at times conflict with windows due to a faulty update, etc. Please let me know which AV you are using.
Follow this tutorial to see if it helps you in any way: Internet Troubleshooting Guide
DO make sure every driver is updated (using another computer and a USB drive, for example). If every driver is updated and you still experience problems, try installing a previous version of the wireless LAN driver.