Registration keys are often version-specific. A key for HexCmp 1.x will not work for HexCmp 2.x.

If you don't run the program as an Administrator when entering the key, the software may fail to save the license info to the Windows Registry.

Disable "Scroll Sync" if you are dealing with files of vastly different lengths to prevent the engine from hanging.

Undo your last edit (essential for binary patching).

To truly get the most out of a hex editor, you need to keep your hands on the keyboard. Navigating through thousands of lines of code with a mouse is inefficient. Here are the essential hotkeys for HexCmp 2: Navigation & Comparison Jump to the next difference between the two files. Shift + F6: Jump to the previous difference. Ctrl + G: Go to a specific offset (address).

Copy-pasting from an email often includes a hidden space at the beginning or end. Try typing the key manually if the paste fails.