1.While you are logged on as an administrator, click Start, and then click Run.2.In the Open box, type regedit, and then click OK.3.Locate the appropriate registry subkey, right-click the IsInstalled (REG_DWORD) value, and then click Modify.

To reinstall only the Internet Explorer 6 browser component on Windows XP, use the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{89820200-ECBD-11cf-8B85-00AA005B4383}

4.Change the value data from 1 to 0, and then click OK.5.Quit Registry Editor, and then install Internet Explorer 6.