How do I Escape an Ampersand in a REG_SZ String?
REG_SZ strings are just strings. They don't have anything that needs escaping.
Menu items are where the & character becomes special. In menu item titles, it indicates that the following letter will become the keyboard shortcut (mnemonic) – e.g. Ob&fuscation will make the F key select the menu item, and the letter f will be underlined.
To escape the ampersand in menu items, it has to be doubled, e.g. Obfuscation && Packing.