Why did you reinstall the all in one? SP-2 install perhaps?
Since the reinstall did not provide all the previous features--
Was the same version driver and application software reinstalled? Is a newer
version available on HPs web site?
Is a network interface such as ethernet or wireless involved (built in the
all in one for instance?)
Did HP mention a "cleanup" utility that needed to be run before you
reinstalled? One may be available on the HP web site.
Did you uninstall the old all in one driver and software before you
reinstalled, or just do a reinstall over the old?
What usually happens in cases like yours is that the registry entries
associated with the all in one get damaged, or a bare bones driver gets
installed by mistake.
Often, a reinstall over the old install (for whatever reason) does not
properly overwrite the old entries. and just adds new entries or leaves the
old ones in place..
When all else fails, a possible cure is to uninstall the port and port
controller driver software (USB usually). When windows restarts, it
normally reinstalls the port and controller. If the all in one was
disconnected, and the all in one driver and possibly HP application software
was uninstalled prior to shutdown-restart, the USB port and controller
driver reinstall generally causes enough of a change to set things up for a
successful reinstall of the all in one software and drivers.
There are some cautions--
You may need a PS-2 interfaced keyboard and mouse instead of USB.
Your motherboard may require the reinstallation of chipset specific drivers
instead of the generic windows USB drivers.
Follow the all in one install instructions exactly. Connect the all in one
only when told to do so.
Manual registry editing is possible, but is very unforgiving, and can cause
other more serious problems. Thus it is more or less a last resort.
The basic idea used in manually editing the registry is to remove any
entries associated with the all in one. Finding the entries is a fairly
major effort, and involves entries referenced by other entries. It's not
uncommon to find multiple, almost duplicate entries, due to the presence of
multiple USB ports.