Latitude e7440 5570 hspa+ mobile Broadband win8

Good morning everyone.
I have a big problem with Latitude "e7440."
With Windows 8,  "DELL WIRELESS 5570 HSPA + Mobile Broadband Mini-Card" does not work.
On the website of DELL, I found a type of driver, but installing it in the device manager, does NOT work, recognize Micro Sim but not connect (with windows 7 on the same model of laptop and the same sim no problem) i have update the bios but not work. How do I proceed? Can someone help me, please? I have purchased 50 "e7440" and all with win 8 have the same problem.
Thank you.