I was having exactly the same issue. My dell xps 13 would lose wifi connection from time to time, reconnect, lose it again and so forth for a couple of minutes. Then it would work ok for a while, but show the same problems an hour or two later.  In the support forums, some users suggested the problems may be caused by the new network driver (7.35.295.0). If you have this driver, try to revert to the old one (6.30.223.227). I downloaded it from this site (www.dell.com/.../DriversDetails), deinstalled the new one, deleted it from the system, and then installed the old version.  So far the old driver works and none of the abovementioned problems reappeared. Hope this helps. Good luck. 
Dear all, I own a brand new Dell XPS13 for around 4-5 weeks now and same as several people around here, I'm having serious connectivity issues & signal strength with my onboard network adapter. The interesting thing I'd like to share here is that the onboard Dell network adapter seems to underperform only when used with Win10. Let me get the story straight from the beggining. The laptop purchased with Win8.1 Pro preloaded. I've upgraded to Win10 since the very first day of purchase so I didnt have previous experience of how the laptop works. This is where i noticed two things a) Network connection has been occasionally lossing connection ti network and also being unable to reconnect or locate avail.networks (unless I was making use of the troubleshoot menu). This had been happening quite often. I tweaked the powersaving settings for the adapter , but didnt help. b) The worse problem was the wifi-range of the laptop was EXTREMELY poor. I was losing complete access to networks/modems even when i was getting 5-7 meters away from them (no walls necessarily in-between).That was extremely frustrating as it was impossible even to connect from my office to company's modem which had been 7-10 meters away. My laptop was pretty useless so i needed to buy an extrenal usb device (booster) so to be able to connect to networks.  I thought that the laptop had issues...shame for such a delicate product to be so poor in performance. A series of blue screen incidents (crashes) forced me to make a re-installation of windows hoping that it was a software error. WHEN I ROLLED BACK to Windows 8.1 Pro , the machine was working perfectly.-No more lost connection incidents -The range of my on board Dell Wi-Fi adapter was now very good (making the booster useless) as i was able to access networks that previously been inaccessible. Thinking that this could be the initial's Win10 Installation issue, I made a second attempt to re-install Windows 10.Once installation was complete, my XPS begun having the same issues again.Very short Wi-fi range & disconnections. I also started having the blue screen incidents as a result of unreasonable Memory usage peaks So , I've decided to stick with Win8.1 now...(even if i dont like em at all) My question is...Has Dell's Engineers located these particular issues (i have other people with latest XPS models having the same short range issues on Win10) ??? Is there a fix underway for these? I'm now 200% certain that its a software related issue that has to do with Win10 in specific. Maybe someone managed to resolves these issues somehow?? I would really appreciate some help       
Wireless Adapter issues on XPS13 on Windows10