Microsoft has found a flaw in some versions of Windows that could allow attackers to reformat a machine's hard disk.
In its 65th security bulletin issued this year, the company warned that two types of computers are at particular risk: those used for browsing the web or reading email, and those hosting websites using Microsoft Internet Information Services.
Windows XP is not affected by this issue, but anyone using Microsoft Windows 2000, Windows Me, Windows 98 SE, Windows 98 or Windows NT 4.0 needs to download a security patch, available here.
The vulnerability could allow an attacker to target Windows-based systems and take action such as changing web pages or reformatting your hard disk.
The security alert is the first to be issued in a simpler format, which Microsoft adopted due to complaints that its bulletins were overly detailed and confusing.
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