I have a dell xps l502x running on windows 7 home premium. I recently bought a 5550 wwan card ( Ericsson F5521gw 2XGNJ) for which i tried installing dell wireless 5550 driver. it was not successful and i got the message saying authentication failed and no compatible device detected!!! Windows device manager identifies the card as "OTHER device F5521gw" which probably means that the hardware is installed properly.
I have tried installing this Driver Details | Dell US driver multiple times and every single time i got a message saying
"Driver installation failed. No compatible Dell Wireless HSPA Mini-Card has been found on this computer. Please insert hardware and restart the driver installation.