
Explanation

Box 1: String1 will be deleted.
To delete a value, append equals and then minus to the value. For example:
"String1"=-
Box 2: Value1 will have a value of 1
@="2" sets the default value to 1 but Value1 already has a DWORD value.
A DWORD (32-bit) value is a hexadecimal value. Value1 is 0x00000001 which is 1.
References:
https://www.computerhope.com/issues/ch000848.htm
https://www.computerperformance.co.uk/vista/reg-create/