Your system specs show windows XP, so I do not know what edition of Windows 7 you have. Personalization is not available in Windows 7 Starter edition
In all other editions it is found by clicking the titel Appearance and Personalization
and the clicking Personalization
(Control Panel Category view) or clicking Personalization
(Control Panel Icon view). It is also found in Desktop context menu as Anthony told above.
Control Panel Category view:
Control Panel Icon view: