It is possible the driver was in the old kernel. It may not be in the new kernel you loaded.
OR did you load a module to support your NIC using modprobe ? Have a look as root using the command 'lsmod' to see if you have a module loaded to support your NIC. If not, you will need to load one.
If you need help figuring out what to load, as root run the command 'lspci' and post the results. I hope that will provide enough information to figure out what module to modprobe.
Then you will need to configure and activate the interface.