Indicate the placement of the value in the Value field relative to the specified environment variable's existing value. Select one of the following options from the drop-down menu:

- Append This option appends the value indicated in the Value property to the end of the specified environment variable's existing value.
- Prefix This option adds the value indicated in the Value property to the beginning of the specified environment variable's existing value.
- Replace This option replaces the value of the specified environment variable with the value indicated in the Value property.

If you select Create for the On Install property and the specified environment variable already exists on the target system, the Placement property value indicates how the new value should be added to the existing environment variable's value or if it should replace the existing environment variable's value. However if—in this scenario—the specified environment variable does not exist on the target system, it is created and the Placement value is ignored.