That's because the & is an operator (for concatenation) to Access, so unless
you "tell" Access otherwise, it is treated as such.
To make it show in the label, use a double one (&&), which will only show
one on your form.
The & is used to make the next character underlined. This underlined
character becomes a quick key to activate that control. For example, if you
typed
Click &Me
The M would be underlined and Ctrl+M would take you to that control. For a
button, it will also activate its OnClick event, I haven't tried it with
other controls. To get the & to display instead of causing the underline,
use 2 of them &&.