I've been trying to install Xgl and Compiz, but right now all that matters is fixing what I've edited while trying to install them. I've really no idea what I've done, except follow the instructions at ubuntu.com, but I do know that I changed some things in the xorg.conf file.

My first problem, after reconfiguring the xorg.conf, was the login page. White lines appeared all over, and although I could type in my username/password, the word "Password" does not appear at all. I was able to log in, so I thought, Hey, no big deal, just one little blip.

Wrong. Once I started Firefox, here's the link to the screenshot of what happened to the window:
http://i33.piczo.com/view/f/f/k/d/2/...23_98391_2.png
Some other applications work this way, too, like Help and Support, Open Office and some games don't work too well, either.

Anyone know what I need to do to fix this? Any help at all is very much appreciated.

Fancy effects

The first thing I would check is that the HorizSync and VertRefresh settings are appropriate for your monitor. You'll have to get those settings from your monitors manual (or the web), then check the settings in Section "Monitor". The section should look something like this (with appropriate settings, depending on your monitor):

Normally, the VertRefresh would be a range like HorizSync (the single value on mine is because Ubuntu didn't like my monitor much).

Try looking in /etc/X11/ for xorg.conf.*
(Where the star is in the above example, there should be a string of numbers. e.g.: xorg.conf.20070630210834
The string of numbers is a date and time)
This will be a backup of the display settings. I would do this: (as root)
rm xorg.conf
mv xorg.conf.* xorg.conf

(Remember to replace the star with the series of numbers you saw above.)
then restart X. (Control+Alt+Backspace)
This will revert your display settings to what they were before they were changed.
If this doesn't work, try running:
dpgk-reconfigure xserver-xorg as root. And reconfigure your graphics. This will make a new xorg.conf

Wow. I'm in awe.
I tried both things you guys suggested, and I don't know what happened (especially considering I'd done those things over and over again), but it worked !

THANK YOU SO MUCH!

Seems I spoke too soon.

While I was logged in as root, everything worked perfectly, but then I restarted my computer and tried logging in with my own username and everything went back to the way it was.

Any ideas?