Not too sure if this will help others, but wanted to post here what I have seen out int he world as well in regards to this issue.
I have installed Windows 7 on hundreds of PC's (old and new). A vast majority of them were installed here at my house and tested, updated and burned in before I allow them to walk out the door. So here at the house, I have no issues with any of my computers dropping network connections. The hardware will vary greatly depending on what they are purchasing, however, one thing is always constant, they work when they leave.
Now, I have had people call me and tell me they have issues with their networks dropping constantly when they get it home, however, if they bring it to me, we can never replicate the issue. I went to people's houses and saw the issue myself and spent many hours working through this step by step.
After messing with things here at at their houses, I have found that their Routers were the cause of the issues. Now, it's not that their routers were not working, it's just that with Windows 7, IPv4 and IPv6 are running so if your router is not able to fulfill the IPv6 requests or ignore them, for some reason it will drop all network connections for that PC until you re-obtain an IP, however, it will then drop again after a bit.
To solve the issue, I just simply turned off IPv6 on the PC and no more network drops.
Start > Control Panel > Network and Internet > Network Sharing Center > Change Adapter Settings > Right Click/Properties on your network connection > Uncheck "Internet Protocol Version 6 (TCP/IPv6)" > Reboot (just to be sure)
I can't say this will help with ALL the issues, but I hope this will solve the problems if some.
I am working on compiling a list of routers that I know I have solved with this and will share it when I get it together.
Thanks all!