This is the latest Intel Wireless Driver for Windows 8.1 required to update into Dell XPS 13 series. This will solve the problem on wireless connections not stable and also issue where limited and no internet access to certain wireless router.

Please click on the link below to download latest Intel® Dual Band Wireless-AC 7260 driver. Remember to remove the existing driver prior updating the latest copy, File name: Wireless_17.0.3_e164.exe.

Intel® PROSet/Wireless Software for Windows 8.1:
https://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=23942&lang=eng