Failure on display driver update

Prior to installing new colorimeter hardware I made the
mistake of following the instructions and attempting to
update my video display adapter.

I have ATI xpert 128 - the update failed, at least partly
my own fault for failing to spot the instruction that said
remove the old driver first.

result is that no ATI driver is installed - when the card
is installed I get no input to the monitor (fine in DOS
setup but when windows loads the screen goes blank -
windows 98SE) and the monitor indication no input.

Have tried many combinations of switching to another
monitor (same result) and swapping back to the prior video
card (which works) fine - but can't seem to get that darn
ATI installed again.

Any ideas?