i press the on button looks as if it will start and then goes to a blue screen. it says unmountable_boot_volume. then quite a bit of info on maybe i added software and need to remove it. has this stop 0x000000ed (ox820721A8, 0xc0000006, 0x00000000, 0x00000000)
i used it fine. went to a customer and used their overhead projector that plugged into my computer. Ran whole day fine. Unplugged shut down and went to my hotel room and tried to turn it on. After trying to come on went to the blue screen. I did try last known configuration . etc. this is 14 months old HP pavillion dv4000 laptop. never a problem prior.??HELP

Here are the basics:

http://support.microsoft.com/kb/297185