If i recall, back in the day of those Packard Bell, i am pretty certain this is what you have to do.
Find the spot on the mobo that says CMOS. It will have 3 pins with one jumper on it. The jumper will be on pins 1 and 2. Move the jumper so its now on pins 2 and 3.
I believe you leave the battery in and reboot.
Then when that happens you can try to get into the bios, i believe you press "delete" button, but it could be another button, it says so if you get to the first screen after the packard bell insignia.
But if you cant get into the bios, then go ahead, move the jumper like i said, turn the computer off and then back on, see what happens. Then turn it off again.
Then go back and move the jumper back to where it was before. Then try and boot. If nothing, turn off and try and boot and try and get into bios (cmos) again by pressing delete key. If that doesnt work then turn off and on again and try the F1 key instead of the delete key, if that fails try the F3 key, or the F6 key, or the esc key, or the space bar, or the enter key.
If all this fails, then go back to the beginning and do what i said about the jumper, moving it to pins 2 and 3 from pins 1 and 2 where they start out from.
But this time, take out the battery, and then repeat all the steps above, trying the delete key, F1 key, etc, etc.
Sometimes the password is set on these and this re-set of the bios clears the password if there was one.
Let us know how you make out.