With increasing concerns about Windows OS in general, and Vista specifically, I've decided to explore the possibility of survival in a non-Microsoft OS. In the article What's the best Linux for beginners?, the version that seems to be the best fit for me is Xandros Professional. Though many applications are written for Linux, some are not. For that, Crossover allows the running of Windows applications.
I downloaded the trial version of Xandros Professional and installed it on my D-drive. It installed a dual-boot wedge on the C-drive so on boot, it presents me with the option of running Windows XP from the C-drive or Xandros Linux from the D-drive. Xandros runs well and connects to the internet fine. But now, Windows XP doesn't "see" the network adapter -- I'm getting the error msg "Network Adapter Unplugged". (It's a Broadcom 440 in a Dell machine.) I've tried a number of things to resolve the problem: a true cold boot (powering down for 10 seconds, then turning back on), rebooting the network router and cable modem, and disabling and reenabling the network device in Windows, all to no avail. I left the machine off for 20 minutes and when I came back and rebooted, Windows XP once again "saw" the network adapter. I then rebooted to Linux, which worked, but when I rebooted to XP, once again, it didn't see the network adapter.
So even though Linux is installed on a completely different drive, and I cold boot from one OS to the other, it still interferes with the machine's network adapter. In further experiments with longer cold boots, I considered installing a second network adapter, dedicating one to XP and the other to Linux to avoid this problem. Then, I reinstalled Windows XP... but the network card still refused to work.
It finally occurred to me that if Linux could mess up the card, maybe it could fix it. Instead of running Linux from the D-drive, I inserted a CD copy of Mepis Linux and ran it from the CD. The network card worked fine (as it always has within Linux). But then, after rebooting the computer, the network card once again worked from within Windows XP!!!
There may also be a software solution, getting Linux to release the network card as it powers down. But for me, the solution will be to dedicate a separate machine to Linux, not allowing it to run at all on the Windows machine.