So, how to block them and enjoy secure computing? The bitdefender Windows 7 free firewall is by default turned on that block unwanted access. Windows XP operating system boasts built-in firewall and in Windows 7 this integrated firewall has been beefed up. Although Windows 7 operating is an excellent operating system comprising a number of robust security features but still there are some loopholes which allow the hackers to access to your computer. If the answer is yes, this article is worth reading.