Re: Connected to two networks when Windows 7 is booted
Flapperbol:
Hello and welcome to the forums.
I know recently we've seen some issues with gig cards and the autonegotiation feature causing some similar issues. I assume that since the board has two gig cards integrated that you are using one of them. The issue could be a driver issue with the card or possibly a firmware issue with the router but since everything seems to work fine after you jump through a couple hoops, just as a test try this;
Type ncpa.cpl into the search box and hit enter
select then right click the card you are using and choose properties
near the top of the properties dialog box click the button that says configure
in the resultant dialog box, in the left frame/column look for something called Speed & Duplex and select it
In the right column labeled "Value:" use the drop down arrow and select 100 half
OK your way back out of there and reboot.
See if the problem persists after applying this work around.
Yesterday was, Today is, but ahh Tomorrow...mystery, suspense and a promise of hope.

Operating System Windows 7 Ultimate 64 bit
Computer Type Home built
OS Service Pack Service Pack 1
Internet Explorer Version IE9
DirectX Version 11
CPU Type and Speed AMD Phenom II X6 1090T Black Edition Thuban 3.2GHz
CPU Cooling Stock Factory Cooler
CPU Idle Temp 32C
Motherboard Chipset GIGABYTE GA-870A-UD3 AM3 AMD 870
System BIOS Revision Award F5a (beta) 11/15/2010
System Memory Type G.SKILL Ripjaws Series 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666)
System Memory Speed 1333 currently underclocked to 1066
System Memory Clocking 7, 7, 7, 20
Video Card Type and Speed Nvidia GeForce GTS 450 1Gig DDR5 DX11
Video Card Cooling stock
Video Card Temperature 32C idle
Power Supply Unit (PSU) Antec EarthWatts EA750 PSU
Computer Monitor Dual Dell ST2320L
Sound Card Integrated RealTek HDA
Speakers Klipsch
Headset/Microphone Altec Lansing
Hard Drive Two Seagate 500 gig SATAII's ST3500418AS ATA
Optical Drives Lite-On DVDRW x2
Keyboard and Mouse Logitech USB Optical
Modem-Router Type Arris MODEL: TM602G / Microsoft MN700
Network Adapter Realtek RTL8102E/RTL8103E Family PCI-E Fast Ethernet NIC
Printer HP InkJet 990cxi
Network Speed WD Passport 500gig USB 3.0 BackupDrive
USB Controller NEC Electronics USB 3.0 Root Hub
Gaming Console Xbox 360
Anti-virus Software Microsoft Security Essentials
Productivity Suite Office Pro Plus 2010
System Install Date 2011-01-25 21:59:23 on this drive
Computer Skill Level Certified Professional
Windows Experience Index 7.2
Favorite Game FarCry (original, 2 sucked)