I've got a co-worker who just got a new laptop, and she wants to
transfer all her files (about 20 GB) from her old laptop to the new

Both laptops have USB 2.0 ports, and both have ethernet. Old one runs
Windows XP, and new one runs Windows Vista.

I have (created) an ethernet crossover cable, and tested it to make
sure it works.

My questions are:

If I use the ethernet crossover cable to transfer the files, will the
copy process properly check for and correct errors?

Would a USB file transfer cable be more reliable?

Ideally, I would create an archive, and verify the SHA1SUMs, but this
would take too much time. If the Windows copy command has built-in
error correction, that's what I need to know.