From PE Viewer:
PE Viewer is handy and user friendly tool for viewing PE structures. It has editing feature to modify PE headers for learning purposes or fixing invalid PE files. Use the tool to view Imported DLL's and functions of any Windows 32 or 64 bit files. Find out what functions are exported and what offset the functions start execution. This could be a great tool for beginners who want to learn PE file structure. It is also very good tool for virus/spyware analysis.