Khow123,
Did you install the drivers in the correct order? How to Download and Install Drivers in the Correct Order
Start with the Dell System Software, v.7.0.1, A01
then install
Intel Management Engine Interface, v.6.0.0.1179, A00
Ricoh Card Reader R5C833, CardReader R5U230, v.2.07.01.04, A04
Then install...
Realtek RTL8111DL Ethernet Controller, v.7.006.0820.2009, A04
The go to Dell Warranty Status enter your service tag, click on orininal configuration. Your wireless adapter will be listed there. Then go to Drivers & Downloads enter your service tag, select your operating system, under network you'll download the drivers and install them for your wireless adapter.
Then download and install Dell QuickSet, v.9.6.21, A07
Places to look to see if your Connection is enabled
That should get you online to get any other drivers needed.
Rick