Hi James,
can you boot into the advanced boot options? Try hitting the F8 key continually when the system is booting. When you get into the advanced boot options screen try the 'Last good known configuration'. This guide will show you how to boot into safe mode which is located in the same place. You want method 2:
http://www.wikihow.com/Start-Windows-in-Safe-Mode In order to help you we need to read the dump file created when your machine blue screened. The Dump files are found in a folder marked Minidump. This folder can be found in the main Windows folder. If you can't find it or no dump files are present then you probably need to change settings so they get created:
Go to Start and type in sysdm.cpl and press Enter
Click on the Advanced tab
Click on the Startup and Recovery Settings button
Ensure that Automatically restart is unchecked
Under the Write Debugging Information header select Small memory dump (256 kB) in the dropdown box
Ensure that the Small Dump Directory is listed as %systemroot%\Minidump << where your .dmp files can be
found later.
Click and apply to exit the dialogs, then reboot for the changes to take effect.
I also moved your post the correct section.
Lastly, James is the lappie still under warranty? I only ask as dropping them is probably one of the worst things that can happen as HDD hate shock of any kind.