Hi again. I have a very little knowledge about unpacking, patching, and assembly. Sorry. Unpacking - This means removing the protection or compression of a PE file (Portable Executable). Some PE files are packed for two major reasons. One is for protection (to help prevent reversing), and the second is to make the file size smaller. There are a lot of packagers/compressors available. Petite and UPX are freewares, and files protected by these tools can be unpacked easily. PECompact, Aspack, Molebox, FSG and others are not free, and you can't easily unpack files protected by them. Patching - In most cases, this means modifying the PE file. Changing some bytes to fix a bug, or to add/remove a feature. Sometimes it also modifies registry entries. Not all patches work the same. 1. Some patches simply modify the existing file. 2. Some delete the existing and replace it with a new one. (Like Microsoft's patches and hotfixes) I don't know that game, and I don't know the patch you are using, but I think it modifies the existing file directly. Unfortunately, there is no way to uninstall the patch you applied. If I were you, this is what I will do. 1. Create a back-up of the original main executable file of the game. (Most patches modifies the main executable) 2. Apply the patch. 3. Download WinHex, install it, and use it to compare the patched and the original file. It will show you the differences between the two files (if there's any). You don't have to unpack it, because it's not packed. Tip: Download RegMon and FileMon from systeminternals and use them to monitor the changes made by the patch.