While this post is a bit outside my "normal" range for this blog, I have posted it because someone might find it in a search and it might save them the hours of searching that finally turned up this information: Microsoft Windows Vista is an Internet dropout.
A friend called me with a problem. Her new Sony VAIO laptop with Microsoft Windows Vista Home Premium would randomly disconnect from the Internet for no obvious reason. The cause turned out to be a simple (and stupid) problem.
Microsoft added networking support to Windows in version 3.11 -- a cobbled-up networking stack lifted (quite legally) from BSD code; the BSD license allows the free use of code if attribution is given. Essentially the same code was carried forward right up to WinXP, but the code was so old and crufty that the BSD distributions no longer used it; hence one of the major changes in WinVista vis-a-vis WinXP is in the networking stack. While some of these changes were much-needed, some just seem arbitrary and counter-productive. One of these changes was the source of her problem.
As far as I can figure, WinVista sends one of its new-fangled packets or messages to an older router or modem, the device says, "Huh?" and WinVista chokes. After hours of research — and booting from a live-booting Knoppix DVD so I could access the Internet to do it — I had WOW (the cable provider) remotely update the firmware in the cable modem and all was well. The same issue may crop up in older routers as well. I realize that many users don't even know what firmware is or are unable to figure out what firmware version a particular device has, let alone be able to update it -- but this knowledge has just been made more important than ever.
I found this tool from Microsoft, but I don't know if it is useful in this context:
Internet Connectivity Evaluation Tool
[This utility] checks your Internet router to see if it supports certain technologies. You can use this tool on a PC running either the Windows Vista or Windows XP operating system. If you're planning to run Windows Vista, this tool can verify whether your existing Internet router supports advanced features, such as improved download speeds and face-to-face collaboration using Windows Meeting Space.
Another related link of interest: Microsoft DHCP bugs make Windows lose networking.
Numerous perplexed Windows users have discovered that attempting to connect their PCs (especially Vista) to their existing networks or Wi-Fi hotspots results in flaky or nonexistent connections.
The solution was not obvious; it took a lot of searching and between-the-lines reading to find this information, but it was worth it -- and I'm glad to share.
A short time later, I ran into a similar problem on a Dell laptop running WinXP. A friend stated that she started having DSL connection problems about 2 weeks earlier; this was confirmed when I couldn't even ping the modem within about 5 minutes after a reboot. I updated her from Service Pack 2 to Service Pack 3 and updated the Ethernet card drivers to the latest version -- no joy. There were no problems with a Linux-DVD boot. Remembering my earlier WinVista firmware issues, I then found, downloaded, and installed a firmware update to her SpeedStream 5100 DSL modem from Siemens; fortunately, the update process was OS-agnostic since it ran from the modem itself, simply looking for the firmware image file on the system. After a reboot her connection was restored under Windows.