What do you mean missing?
do the following please:
Click Start, Run and in the box enter:
msinfo32
Click OK, and when the System Summary info appears, click Edit, Select All (Ctrl-A), Copy (Ctrl-C) and then paste (Ctrl-V) the information back here in your next reply.
You can edit out any personal information.
and while here expand components, expand network and include that info also.
what this means is that you need to download the ethernet (NIC) driver for your pc.