Hi,
If you have restored to several restore points and the problem persists, then it means that the problem was in the previous restore and it wont go away.
To repair the installation of IE you cannot simply doubleclick setup. You will have to do this.
(a) After the system boots and you enter the system.
(b) Open a command dos prompt by clicking Start , Run and then typing the words cmd and pressing enter.
(c) Now you will get a dos prompt window on the desktop.
(d) Insert the Windows XP Setup CD in the CD Drive first and then close the window that appears
due to autoplay.
(e) Go back to the dos prompt and then type this c:/>sfc /scannow Make sure that you enter it in the
same way as shown and now this will check for the integrity of Windows system files and make sure that
none are corrupted. If there are corrupted files then they will be restored from the CD and when the
restoration is complete you will get a confirmation message.
(f) Remove the CD and then reboot to see the effects whether the system has been repaired or not.
Please note that any specific updates that were installed will be lost and you will have to re-visit
Windows Update to update your Windows.