is a Digital8 tape based camcorder.

You *should* be able to connect the camcorder's DV port (not USB) to the computer's firewire port (not USB) with a firewire cable; with the camcorder in "VCR" mode (on the power/mode selection switch), launch the video editor and Capture the video.

What we don't know from your post:

Which Toshiba laptop?
Which ExpressCard? (if Dynex, I've never seen them work - firewire cards from Belkin and SIIG work consistently)...

If firewire drivers came with the ExpressCard, have they been re-installed? Are they for Windows 7 64 bit systems or something else? Have you visited the ExpressCard manufacturer's web site for Widows 7; 64 bit-specific firewire drivers for the ExpressCard?

The original CD will have only USB driver(s) - and other useless software and won't help you. Have you followed the instructions from Sony
http://www.kb.sony.com/selfservice/microsites/search.do?cmd=displayKC&externalId=C86798&fes=true&mdl=DCRTRV250 ? Yes, it matters the order in which things are powered up in the Windows environment...

Have you ever successfully downloaded DV format video (using firewire) from this camcorder to the laptop? Another computer?