How I think it happened

I recently tried to install a different driver on my network adapter because I thought that my ethernet port was causing problems - turned out it was my router and that nothing was wrong with my computer.

Symptoms

Now, my computer keeps hanging when I try to do anything, although System Monitor doesn't seem to register any kind of CPU usage. I'm not 100% sure that the network driver was the issue, but it was the last change I made.

Also, the "Wired network disconnected" message keeps popping up - but only in normal mode and when the computer is hanging.

Another strange thing is that if I start in safe graphics mode, the computer functions normally (most of the time). Also, the problem seems to be getting worse. The first couple of times it started hanging, I reset the machine and it was fine after that. Now I can barely get it to function normally.

It is also worth mentioning that the problem seems to have something to do with startup: if the computer isn't hanging after startup, it will be fine that entire session. If I restart, and it begins hanging, it will never stop.

Are there any possible options for "undoing" whatever it was I did? I would love to just be able to "Restore" to a previous configuration but I don't think that is possible. Is there any way to just uninstall all unnecessary drivers, in case that is causing some sort of conflict?

Information

Ubuntu 12.04 - 32 bit

Intel Core i3

Integrated Intel graphics

additional details

output of lshw -class network - notice that my ethernet card is not listed

 *-network               

       description: Wireless interface

       product: RTL8188CE 802.11b/g/n WiFi Adapter

       vendor: Realtek Semiconductor Co., Ltd.

       physical id: 0

       bus info: pci@0000:06:00.0

       logical name: wlan0

       version: 01

       serial: 88:25:2c:ae:c1:dc

       width: 64 bits

       clock: 33MHz

       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless

       configuration: broadcast=yes driver=rtl8192ce driverversion=3.2.0-48-generic-pae firmware=N/A ip=192.168.1.110 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn

       resources: irq:17 ioport:5000(size=256) memory:d4500000-d4503fff

dmesg output

My dmesg output: http://pastebin.com/kCPJfSdT - notice at the bottom it is filled with

r8101: eth0: link up

messages.