I have a class filter driver that is a lower filter to disk.sys. The
INF used to install the driver is modeled after the diskperf example in
the DDK. The driver installs and runs fine on either Windows 2000 or
2003 but if I perform an upgrade from 2000 to 2003 the LowerFilters
entry in the registry for disk.sys is lost. The entry for the filter
driver in the services key is still intact as is the actual .sys file
in the drivers directory.

Any ideas on how to preserve or re-add the LowerFilters reference
during an upgrade?

One other piece of info is that I notice that neither the driver nor
its INF file are copied to the c:\$win_nt$.~bt\ directory, nor do I
find any reference to it in upsupdrv.inf or winnt.sif. Should there
be?

thanks,
Kevin