Hide woocommerce login form

You miss the required remove_action() parameter — the name of the function to remove. See the Code Reference.

<?php

add_action( 'woocommerce_login_form', 'woocom_extra_register_fields' );

function woocom_extra_register_fields () {
    if ( is_page( 'installation' ) ) {
        remove_action( 'woocommerce_login_form', 'woocom_extra_register_fields', 10 ); // note this
    }
}

I suspect the code you’ve posted is not complete, so, adding the action to remove the action itself looks odd. Simplify things to avoid superfluous operations:

<?php

add_action( 'woocommerce_login_form', 'woocom_extra_register_fields' );

function woocom_extra_register_fields () {
    // check you are NOT on the 'installation' page
    if ( ! is_page( 'installation' ) ) {

        // do your extra fields here

    }
}