1st mistake, buying a used XPS15. Second mistake, reloading Windows from scratch. Third mistake, calling Dell Support.
I have read in various places, including these forums, that whenever you reload Windows on this laptop, you must be very particular about the order in which you load the drivers. I went to where I THOUGHT was the specific loading instructions for my L501x and proceeded to load all listed drivers. Mind you, this LT did not come with a Drivers CD, the previous owner had them in a folder which I transferred to a safe place while I blew everything away. No matter what I do, when I load the drivers after a clean install, I get the dreaded spinning circle of wait. It will finally load the application I click on, but then it starts spinning again when I do anything else. Bottom line everything that takes nanoseconds normally is now taking minutes. Looking at Performance Monitor, no processor or memory hogging going on. So I called Dell support to make sure I had the correct drivers. "No problem" they said, until they found out that I wasn't the registered owner. Ok after 3 transfers, I found out how to have the transfer made. Now I call back on the number Dell gave me and I am told I need to send the machine in for Hardware troubleshooting, here goes another transfer and when this operator answers, he mumbles something and hangs me up doing a hold or transfer. I have wasted so much time trying to get a simple Laptop running. Never had this much trouble loading OS on any other computer and I work with computers for a living! I am totally frustrated with Dell and their support center(s). Oh by the way, if anyone has seen this problem, let me know. I will probably just go out and buy a commercial PC mechanic type program before I will send it in to Dell.
Off my soapbox and on to more important things than sitting on the phone. 