Helllo Frankie,

First of all, why do you want to change directly in base module ?

Make a custom module with a simple view file and paste the following content & your problem will be solved !!!

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="partner_inherit_form_emipro" model="ir.ui.view">
            <field name="name">partner.inherit.form.emipro</field>
            <field name="model">res.partner</field>
            <field name="inherit_id" ref="base.view_partner_form"/>
            <field name="arch" type="xml">
                <xpath expr="//form/sheet/div/div/label[@string='Is a Company?']" position="attributes">
                    <attribute name="string">My Company</attribute>
                </xpath>
            </field>
        </record>
    </data>
</openerp>

Hope this helps,

Let me know still if this is not working,

--

Regards,