I too have gone through a frustrating situation in the Vista upgrade process.

Only mine had to do with my wireless network adapter. The resolution to the problem would be something that I would never in my right mind come to think of. On my laptop, I usually use wireless to connect to my network at work and at home. I started at work when I first did the upgrade from XP Pro to Vista Business. Everything seemed to be going very well, to my surprise after hearing all the horrific stories. Until it came time to connect to my wireless network here at work. The wireless adapter would see the local network, so I click connect. To make things easier on me I had disabled any security or MAC lists on the router itself. Leaving a nice wide open network to connect to. Then I could go back in and enable the security later. No go. I did everything I could think of. I racked my troubleshooting brain and couldn’t come up with an answer. I downloaded and reinstalled new drivers, upgraded firmware, etc. I gave up and went home. Pulled it out to see if I could connect to my network at home. DING! Connected right away with no problems or hesitations. I was totally dumbfounded. Why would it connect at home, but not at work? My router at home is a simple Netgear router. My router at work is a more complicated, but still somewhat simple Sonicwall VPN router. I figured maybe it has something to do with the Sonicwall router at work, since it works fine at home. Thinking there shouldn’t logically be anything wrong with my computer itself. So I call Sonicwall tech support, because at this point I’m frustrated enough that I no longer have the patients to continue on alone. After sitting on the line for an hour, going over everything I’ve already done. Finally the tech support rep decides to go check around with other reps to see if anyone had come across the same problem. I wait a good 20-30 minutes, and finally the rep asks me to go open and edit the registry. Now anytime anyone without any or very little computer knowledge is asked to edit the registry, they should consult someone who knows at little more than they do to help. I’ve learned the hard way in the past. Now I’m much more well versed in the ways of computer programming and how it works. Anyway, buried deep in the registry (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters)he has me look for an entry that I’m suppose to edit but seems to be missing. Confused, I’m on hold again while the rep goes to consult another rep yet again. Finally, assured he has the answer, he has me create a new “DWORD (32-bit) Value” entry line “ArpRetryCount” with the values set all to zero (the default value). I save my changes and restart my computer. As windows comes back around, I wait eagerly to see if something as simple as this could in fact have such a satisfying result. What do you know, it worked. Unbelievable. Now with problem resolved, I find a computer that had a fresh Windows Vista installation to see if in fact that same problem existed. Indeed it did. The same registry line that was missing from my upgraded version was also missing from a version that was a clean install. So if anyone runs into this same problem I hope this was of help to you.