An aside to The C:
You are mistaken! Packard Bell is NEC, not HP (Hewlett Packard)!
Open the device manager, expand the DVD/CD-ROM drives (click the +). Then right click the NEC drive entry and scroll down and click properties.
In Properties page, click the DVD Regon tab.
Near the bottom you will see a box labled Current Regon. If the entry matches the disks you are attempting to play, regon setting is not your problem.
If the current regon setting does not match, you can change it to match by selecting the appropriate country from the scroll down list an then clicking "ok"
CAUTION: The regon setting can only be changed 5 times, and then the drive is "frozen" to the last regon set. Please read the text at the top of the propertiys box.