The HKLM path is generically:
HKLM\Software\Adobe\(product name)\(version)\AVGeneral\bValidateBytesBeforeHeader=dword:00000000
For example, to change the behavior for Acrobat 11.0, create a DWORD at this location: HKLM\SOFTWARE\Adobe\Adobe Acrobat\11.0\AVGeneral\bValidateBytesBeforeHeader=dword:00000000
The HKCU path is generically:
HKCU\Software\Adobe\(product name)\(version)\AVGeneral\bValidateBytesBeforeHeader=dword:00000000
For example, to change the behavior for Reader 10.0, create a DWORD at this location: HKCU\SOFTWARE\Adobe\Acrobat Reader\10.0\AVGeneral\bValidateBytesBeforeHeader=dword:00000000
Always change the product and version number in the preference path to match your installation. This method allows the PDF to display on machines you control.