Thousands of Windows XP users were blocked from accessing the internet this week after they applied a misfiring antivirus update from Kaspersky Lab.

The issue affected both consumer and business versions of Windows XP. Vista or Windows 7 users were untouched by the snafu.

Even so, Kaspersky’s support forums quickly filled up with complaints from frustrated users and hassled sysadmins.

Kaspersky’s since been in touch to say:

Kaspersky Lab would like to apologise for any inconvenience caused by this database update error. Actions have been taken to prevent such incidents from occurring in the future.

It added:

The problem only affected x86 systems with the following products installed: Kaspersky Anti-Virus for Windows Workstations 6.04 MP4; Kaspersky Endpoint Security 8 for Windows; Kaspersky Endpoint Security 10 for Windows; Kaspersky Internet Security 2012 and 2013; and Kaspersky Pure 2.0.

Souce: The Register