I am reporting on a fatal "Printer Driver Conflict" which I encountered and verified with new versions of Hewlett Packard Pavillion OS involving at least its printer driver groups and erroneous coding affecting the OS's Hal.dll file. Thus far, it appeares HP has not under taken the proper initiative to correct it. I confirmed it after it manifested itself and destroyed my OS in a Pavillion PC received in early September 2005, and presented itself again in the new 11 CD OS replacement set shipped to me in early November 2005. The problem exists with two program driver groups that HP includes with its latest Windows XP OS, with the Photosmart driver group, and PSC driver group. It can occur if you have an HP printer, and when you go to install the driver during PC setup. The OS will not accept your printer's driver, rather, it requires you to accept the OS's newer driver - and there is some bad exe coding that then will destroy the critical Hal.dll file. You will initially notice slow PC speeds, freeze-ups, some boot problems, and failures during printing, and eventually your PC will not boot up at all. At this juncture, boot up tests will reveal a fatal Hal.dll err - which cannot be corrected w/o a full reinstall of your OS, programs, and all data files. The solution, as I discovered and worked through with HP, is to unstall these two HP printer driver groups from the program menu. The OS will then accept your own existing driver for your printer. But be careful, after I thought these 2 driver groups were uninstalled - they still appeared under the list of OS programs. After clicking "uninstall" from this location, the OS recognized that the program groups were uninstalled, but identified that not ALL of the files were removed - and instructs you how to remove the remaining files. Hope this might prevent the days of work and lost data I had encountered.