Here's the situation: I had a working network setup on my Debian box, with two Ethernet interfaces being reported by `ifconfig` - eth0, and eth1. eth0 is an onboard Realtek NIC, and eth1 is a D-Link PCI NIC. Sound, however, was not working on the system.

Following the advice on [this page](https://wiki.debian.org/ALSA#Alternative_Method), I went to [Realtek's website](http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=13&PFid=5&Level=5&Conn=4&DownTypeID=3&GetDown=false) and downloaded the "LINUX driver for kernel 3.x and 2.6.x and 2.4.x". I unzipped it, and after installing the necessary build and Linux header packages, I ran `r8168-8.037.00/autorun.sh` as root. *Upon review, I made a big mistake here.* I clicked on "Realtek PCIe GBE Family Controller Series Drivers" rather than "HD Audio Codec Driver", so I installed their networking driver instead of their audio driver. Oops. In any case, I am now looking for a way to undo this mess.

No error messages seemed to be output, but sound was still not working, so I rebooted the machine. When it came up again, `ifconfig -a` now only shows me the `eth0` interface and not `eth1`. Also, `find /sys/devices/ -type d | grep eth` only returns me `eth0` devices, and no `eth1` devices. Nor does `dmesg | grep eth1` give any output. Somehow the new Realtek drivers have prevented `eth1` from being detected! Sound still isn't working, by the way.

How is this happening and how can I fix it? I guess I'll have to live without sound but I want to get back my working `eth0` and `eth1` configuration. How can I get Linux detecting `eth1` again?

It looks like it may have installed some stuff into `/lib/modules/3.2.0-4-amd64/kernel/drivers/net/ethernet/realtek`, if that helps. For example, the `r8168.ko` file is in both the `src` directory of the drivers I unzipped, and in that `/lib...` directory.