Internet Explorer 6.0 is installed with Windows XP and there is no standard way to reinstall it.
If you need to reinstall it:
1. Log on with administrative privileges.
2. Use the Registry Editor to navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components{89820200-ECBD-11cf-8B85-00AA005B4383}.
3. Right-click the IsInstalled Value Name, a REG-DWORD data type, and set the data value to 0.
4. If you wish to reinstall Outlook Express 6.0, navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components{44BBA840-CC51-11CF-AAFA-00AA00B6015C}
and right-click the IsInstalled Value Name, a REG-DWORD data type, and set the data value to 0.
5. Quit the Registry Editor.
6. Download Internet Explorer 6.0 and install it.