From Realtek Semiconductor:
Realtek RTL8168/8111 PCI-E Gigabit Ethernet NIC: The Realtek RTL8168 Gigabit Ethernet controller combines a triple-speed IEEE 802.3 compliant Media Access Controller (MAC) with a triple-speed Ethernet transceiver, PCI Express bus controller, and embedded memory. With state-of-the-art DSP technology and mixed-mode signal technology, it offers high-speed transmission over CAT 5 UTP cable or CAT 3 UTP (10Mbps only) cable. Functions such as Crossover Detection & Auto-Correction, polarity correction, adaptive equalization, cross-talk cancellation, echo cancellation, timing recovery, and error correction are implemented to provide robust transmission and reception capability at high speeds.
January 31, 2011
Version: Realtek RTL8168/8111 PCI-E Gigabit Ethernet NIC 5.642.324.2006
Nothing- not a thing.
For whatever reasons it stops the PC/MOBO recognising the modem, and stops you getting any network connection.
This update causes a conflict error of some sort. On top of that (how I don't know) it screwed my MOBO up royally, as each component failed systematically - first USB ports, then graphics card and a whole heap of other bits with BSODs gallore.