Upgraded Memory, loose the internet?

I recently bought and upgraded my system's memory from 2GB to 4GB. The system had one set of CORSAIR DDR2 800 2GB dual channel TWIN2X2048-6400C4 memory sticks installed and everything worked fine. I then bought another set of the same memory and installed it (making it 4 x 1GB) However, when I turned the computer back on, windows detected 3.4 GB of memory, as expected, but could not detect either GB LAN ports on the motherboard, and thus I lost internet. I removed the RAM back to the original 2 GB and like magic the LAN ports and internet came back. So how does upgrading the memory cause me to loose internet?

My system is:

MB: M2N SLI Deluxe
OS: XP Pro SP3 32-bit
RAM: 2 x CORSAIR DDR2 800 2GB dual channel TWIN2X2048-6400C4
CPU: AMD Athlon 64 X2 6000+

You are using a 32 bit operating system and as a 32 bit operating system it can only address up to 4GB. In round numbers XP can only address 4GB.
Your video card has XXXMB of ram on the card so that limits XP to 4GB minus the cards XXXMB of memory. In addition other hardware also takes away additional amounts of memory for overhead (usually a small when compared to the video card) and the remaining memory (address space) is available for Windows XP and your applications. So that 4th GB of ram you installed or will install is mostly unused.

A link to the white paper titled "Gaming Performance Analysis" by Corsair
Memory Inc. provides a good clear explanation of how a video card effects
the amount of available memory in your PC.
See: http://www.corsair.com/_appnotes/AN8...e_Analysis.pdf

Intel Chipset 4 GB System Memory Support
http://www.dcomputer.com/ProInfo/sup...1/4GB_Rev1.pdf

Vista Users with SP1 now report how much physical memory installed on your
computer:
See: Windows Vista SP1 includes reporting of Installed System Memory (RAM):
http://support.microsoft.com/kb/946003

RAM, Virtual Memory, Pagefile and all that stuff:
Basic information about the Virtual Memory implementation
in 32 bit versions of Windows 2000, XP, 2003 Server etc.
http://support.microsoft.com/kb/555223

As far as the loss of the ethernet controller.... I cannot answer that .... unless the OS has re-mapped the memory addresses and has left out the network controller .... in which case I would delete the controller from the hardware device list and re-boot and let windows "find it" and automatically allocate the memory address for it...... It's worth a try.....