At the information age, more and more affansion is paid to PCs' information protection. Firstly the principles of Personal Firewall is introduced, and the disadvantages of some typical PFW products is analysed in IP filtering, port protection, exploit protection, and process protection. Hence, the concept of enhanced personal firewall is brought out. After that, the designation and technical methods of EPFW's IP filtering, port protection, exploit protection, virus protection and process protection are illustrated. All these show that EPFW is a reasonable way to solve the problem of PCs' information protection.