Re-boot into a DOS window. Do this by selecting Shut Down and from the drop down menu, select Restart in MS-DOS Mode.
When you get to the command prompt, it should look like this;
At that prompt type the command;
that is scanreg, a space and then /restore. The complete line will look like this;
and select the Enter key.
This will start the registry restore utility, which in turn will give you the last five good registry backups. They appear in USA style date mm/dd/yy. Pick a date PRIOR to your crash and select the restore button. This is done by using the arrow and enter keys.
This will set the machine back to a time prior to your problem and if it's a registry entry that's causing your grief, with luck, it will resolve the issue.