HI Guy , I had problem with the SD card reader after I upgraded my windows 7 to windows 10 . After checking my other laptop pc's, I figured out that only this model (XPS L401x) is effected . So I had to do some digging and mining and research, I figured this menthod.

1. download the right drivers from this link : Intel SD Host Controller Drivers Download for Windows 10, 8.1, 7, Vista, XP .

2. Follow "To install the drivers:" in this link : Solved: Yoga Tab 2 1051-F microSD Card not reading after u... - Page 2 - Lenovo Community

After doing this , I opened my Device Manager and right clicked the intel SD Host Controler, under SD Host adapter and run Update Driver Software . There however will be warning sign hanging there , but what can you do Microsoft employees are only drawing paychecks but tired doing the same thing again again and gave us the ---- of Windows 10.Lets Live with it. My SD Card reader runs like 1/4th of a second (FAST). Cool Right ? Do it ! and save your Chicken from burning.