After Windows Xp SP3 Installation you cannot uninstall Windows Internet Explorer 7 or Internet Explorer 8 Beta 1.

To uninstall IE from your system you need to revert Service Pack installation , and only then uninstall Internet Explorer

Follow MS SP Removal Guide

Note: This issue does not occur if you Install IE after SP3 installation

Internet Explorer 7 The version of Internet Explorer 7 packaged with Windows Vista includes a number of advanced security technologies that make this the safest version of IE yet. In this section you’ll examine the many security features Microsoft added to Internet Explorer 7. These features were absolutely necessary: Ever since Microsoft integrated Internet Explorer with the Windows shell beginning in the mid 1990s, Internet Explorer has been a major avenue of attack against Windows. With Windows Read more