I would suggest to try to login in Safe Mode, while the laptop is booting up repeatedly press on F8 until it loads Advance Boot Options and select Safe Mode. If these doesn't work last option would be to try and use an external keyboard and see if that will work or not. If all these steps will not work I would suggest contacting Packard Bell regarding password related concern.
Leave the keyboard plugged in
Cut off the computer. (note you still see a light inside even when it is unplugged)
Unplug the CPU power cord (note light is now gone)
Turn the computer back on.
This worked for me,
Yes I know it is a laptop, The premise is the same, but rather than unplug it you must let it get 100% uncharged.
The ideas is that it never really cuts off until you have pulled the plug or let it die.
disconnect the battery & power adapter to laptop, hold the power button down for 20 count, re-install the battery & turn on the laptop will do same thing. it is called a hard reset as I've done it a few times after reading some of Laptop_Nerd's posts about that.