There is a software called OPJViewer that can be used to open those
JP2 imags.
OPJViewer can be downloaded from the link below
http://www.openjpeg.org
Go on the download and download file named "openjpeg_v1_3_win32.zip"
This is a complete package in which one can find
"OPJViewer03alpha_setup.exe".
Install this and you can then use it to open JP2 files
Hopefully this will help you...
Regards
Imran