Press the Windows key (between Ctrl and Alt) and R, and type this into the box:

thunderbird.exe -p

then click OK.

This was similar to the other directions I got from this forum earlier, which involved typing something longer but similar in the box I got from Run. Neither one of those works. Nothing happens at all. I have Windows 7 Pro, which is new to me, and which I hate so far. I don't know where it stores mail files from Mozilla, but many of those kinds of files are under Local Settings, which is a locked folder, so I am denied access. This could be why I get nothing when following these instructions -- or could it? I don't really know where Thunderbird puts mail files. I used to use Netscape7.2 mail which worked fine in Win X Pro. Most things did, but there was no support for it, and my computer shut down after an electrical outage, and wouldn't boot up, so I had it rebuilt with new hardware and Win7. Had I known about this MS paranoia I Win 7, I wouldn't have agreed to it.