1) I used Laplink to transfer my data, apps, and settings.  I've been using Laplink products for at least 15 years with good results.  This time, not so good.  The big problem turned out to be that I had encrypted my data on my current computer.  Laplink's software didn't warn that this might be a problem, and none of the the technicians I wound up chatting with suggested that it might be.  But after several attempts to transfer my files, and several days of trying to figure out why I couldn't open any of them, I asked whether this could be the problem and the tech said it could be.  Unencrypting the data on the old computer and running the transfer again solved that problem.  (NB: I also tried importing the encryption security keys into the new computer, but that didn't allow me to open the files.)

2) The new computer came with Windows 7.  While I like the Windows 7 interface, I'm finding that lots of software that claims to work with Windows 7 won't install or, or installs but won't run.  So far the list includes ZoneAlarm's firewall and Avast! anti-virus.  I've also had trouble getting Adobe Flash to install.  Currently I can view Flash videos in FireFox but not in Internet Explorer.  I've barely scratched the surface of testing my software and expect many more unpleasant surprises. 

3) No sound.  This seems to be a hardware failure, as I've tried updating the sound card driver, BIOS, and all other recommended troubleshooting steps.  The computer is in the shop now to diagnose (and, I hope, fix) the problem.