Back to it after a much needed break for dinner. It hasn't repaired itself.
Thanks for the above. Trouble is, one of the statements is: get the Sony drivers ready on a stick
before installation.

Never had to do that before.
A Sony site makes the categorical statement that the VGN-NR498E is fully compatible with W7. I have a bad feeling I've messed up by having monitor and keyboard plugged in during the W7 installation. But you'd think it'd be fixable, right?
Vista still fine, and its driver (device manager) shows the same as the duff install. That surprised me. Same as this PC Standard PS2 keyboard.
Kind of at a loss right now.