Hi everybody,

I have this problem and I hope that somebody more experienced will be able to point me in the right direction.
I successfully unpacked program on Windows XP packed with PECompact 2.X. Unpacked program runs on Windows XP fine, no issues. I copied it to Windows 7 32 bit and it fails to run there. After some investigation, I realized that the problem is that Image Base changes and invalidates some memory references in the program and causes unhandled exceptions. I tried to change the image base using LordPE editor to be what I believe it suppose to be, but when the program is loaded into memory it doesn’t use this image base as I would expect.

Please can somebody tell me how to fix this particular issue I am dealing with? How come it does work on Windows XP but not on Windows 7?

Thank you for your help.
Robson

Assuming that the unpacked file isn't using XP hardcoded IAT addresses, you can try turning ASLR off. Open the file in CFF Explorer or other and under Optional Header/Dll Characteristics uncheck 'Dll can move'. It should then load at 0x400000.
Otherwise it could be a .reloc issue, see here for example
http://www.woodmann.com/forum/showthread.php?14494-Pointers-in-unpacked-file-don-t-get-rebased

I unchecked 'Dll can move', saved the updated application binary and the application works like a charm. Thank you.