You can get a Linux Live CD and retrieve the files you need. That is basically a working OS on a CD from which you have to boot. I use Knoppix but there are many distros for that purpose.
I was looking in D:\Documents and Settings\[username]\AppData\Roaming, and seeing the contents of the AppData folder on my C: drive instead. But if I look in D:\Users\[username]\AppData\Roaming, this shows me the AppData folder on the D: drive (from my old Windows install), which is the behaviour I was wanting and expecting.I can only assume that the symlink set up by my old install of Windows 7 has now come to point at the new install of Windows 7, by virtue of it having the same path name. Damn, that's confusing!
On a related note, I tried to copy my "components" folder from the old Program Files directory to the new, but my components didn't seem to be there. I installed them from new, and they seem to be working just fine, but the respective DLLs don't appear in the "components" folder under "Foobar2000". Is that normal?