Maximum Severity Rating: Critical A security issue has been identified that could allow an attacker to run programs on a computer running Microsoft® Windows®. The attacker would first have to send you an e-mail message or entice you into visiting a malicious Web site. You can help protect your computer by installing this update from Microsoft. Products Affected by This Update The following products require updating: Microsoft Windows 98 Microsoft Windows 98 Second Edition Microsoft Windows Millennium Edition (Windows Me) Microsoft Windows NT® 4.0 Microsoft Windows NT 4.0, Terminal Server Edition Microsoft Windows 2000 Microsoft Windows XP How to Check Which Version You Have If you are unsure whether a product you are running is affected by this issue, check the version. To determine which version of Microsoft Windows you are running: On the taskbar at the bottom of your screen, click Start, and then click Run. In the Run dialog box, type: winver Click OK. A dialog box displays the version that you are running. Read more and get the update here.