Elderscrollsinisten,
First, regarding your network boot issue -- your system is only doing this because it has no other device to boot from. As soon as you get an Operating System installed on it, it won't try to boot from a Network. Unfortunately this MSI board unlike most, doesn't have the option to turn off the Onboard LAN option boot ROM separately, so disabling the Onboard LAN as you have done is basically disabling your entire networking card, which, I assume you don't really want to do, especially once you get an Operating System installed. For now, I'd recommend re-enabling the Onboard LAN, and trying to disable "Boot from other devices" in the BIOS boot sequence settings.
As for your OS loading issue, I'm almost 100% positive that your problem is NOT a bad OS installation CD, but either bad RAM or bad RAM/chipset compatibility. I've already had a few experiences like yours with the new K9N series using the new Nvidia chipset.
Basically what is happening, is that your installation CD is attempting to load an Operating System, but in order to do that it has to pass all that stuff through system RAM. Your RAM is having compatability issues or is just plain bad, and the files your OS install CD is loading to your hard drive through your RAM are getting corrupted by your RAM, hence the errors.
There is a very extensive topic regarding this in another thread here in this forum, but before I link you to that, I'd recommend, first, if you are using 2 sticks of dual channel DDR, I'd remove one stick of RAM and try only 1 stick, then load your OS, if you still have problems with that, then I'd suggest downloading memtest86+ (do a google search) and running it for at least 12 hours and/or until you get errors on that memory stick. If you get errors, I'd suggest raising the voltage to your RAM by about 2 tenths of a volt and try running memtest86+ again. If you can run it now without any errors for a minimum of 12 hours, then you are having the same problem many people are having with there K9N based systems. In that, case install both RAM sticks back in dual channel DDR mode, keep the voltage raised and install your OS and it should work now. If you can't make the errors go away by raising the voltage to your RAM then you have bad RAM and you need to RMA it and get a good set.
http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=1153835#1153835
the part of that thread that is pertinent to you doesn't start until I think page 4. I've posted my experiences there and some other people have had similar issues. Incidentally, what type of RAM are you using?
Good luck, I hope you get this solved.