On Windows XP or Windows 2000 PC system with one ZoneAlarm security product installed, user may experience sudden lost of Internet connection and web access after installing KB951748 update, which also known as MS08-037.

KB951478 is a security update for DNS in Windows Server 2003, Windows XP, and Windows 2000 Server (client side). The hotfix or patch makes a major change to the way the operating system handles DNS requests by implementing and enabling source port randomization. The technology prevents and thwarts the ability for hackers with malicious intent to craft or spoof DNS responses by scrambling the address from which a request is placed. The precaution stops the possibility of cache poisoning of DNS servers exploit.

The sudden loss of Internet connectivity error happens with most ZoneAlarm products, including ZoneAlarm Free, ZoneAlarm Pro, ZoneAlarm AntiVirus, ZoneAlarm Anti-Spyware, and ZoneAlarm Security Suite.

As the KB951478 is a very high priority and recommended hotfix (should consider as mandatory), uninstall KB951478 is not a good choice. The fix and resolution is to install the latest and updated versions of Zone Alarm products released by Check Point ZoneAlarm. Check Point ZoneAlarm releases a patch version of 7.0.483.000 to resolve the no Internet access issue with KB951478 update installed. Any version of ZoneAlarm products version 7.0.483.000 or later will be able to work properly.

Download and install the latest versions which solve the loss of internet access problem. The direct download link to v7.0.483.000 is listed here (English only):

ZoneAlarm Internet Security Suite
ZoneAlarm Pro
ZoneAlarm Antivirus
ZoneAlarm Anti-Spyware
ZoneAlarm Basic Firewall