XP's System Restore feature is ideal for such nuances. Go back a day or two.
I just gave my son an old T65 for his XP system. Everthing installed and seems to work fine (including scanning) with the HP XP T65 software.
However, we have the minor problem (apparently well known) whereby the configuration settings/ initialization process comes up either at boot time or everytime the unit is used. Has anyone found a fix for this?