You could try the Repair option, to do this, On the Internet Explorer Help menu, click Repair.
or you could run the repair option from the control panel.
"Click Start, point to Settings, and then click Control Panel. Double-click the Add/Remove Programs icon. On the Install/Uninstall tab, click Internet Explorer 5 and Internet Tools, and then click Add/Remove. Click Repair Internet Explorer"
If there are any errors produced after trying any of the above options, post back and someone will try to help further.