How to repair Internet Explorer in Windows 7 and Windows Vista.

Try Resetting the Internet Explorer settings in Windows 7 and Windows Vista.
In these versions of Internet Explorer, you can repair damaged files or missing registration information. To reset the Internet Explorer settings manually, follow these steps:

• Start Internet Explorer.
• On the Tools menu, click Internet Options
• On the Advanced tab, click Reset.
• In the Reset Internet Explorer Settings dialog box, click Reset to confirm.

Reinstall Internet Explorer

Uninstall Internet Explorer First
Click on Start -->  Control Panel --> Add and Remove Programs.
Locate the Install / Uninstall tab and go down the list until you see Internet Explorer. Now, highlight Internet Explorer and Click Add/ Remove.

How to Reinstall Internet Explorer
Now that you have uninstalled Internet Explorer, you have the choice of reinstalling the Internet Explore that came with your computer or install the most recent Internet Explorer.
1.To reinstall the original Internet Explorer that came with your computer, you can find the IE program on your Windows Restoration disk.
2.Insert the restoration disk and choose to load Internet Explorer, click restore the previous windows configuration or you can choose "Advanced" to specify any additional components you would like to remove.
3.Once you click on restore the IE 6 dialogue box will appear. You will see that it is in maintenance mode, once the setup starts, you can choose to click OK to restore IE.
4.The dialogue box will ask you to verify your choice, click Ok and follow the set up wizard.

How to Install the Latest Version of Internet Explorer
Besides restoring your computer's current version of IE, you can also choose to install a new and improved version of Internet Explorer. Just follow these tips.
1.Visit Microsoft's web site to download the most recent release of Internet Explorer.
2.Click Download to download the most recent release.
3.Select save to your computer
4.Now, uninstall your current version of IE, by clicking on Start/ Control Panel/ Add and Remove Programs.
5.Locate the Install/ Uninstall tab and go down the list until you see Internet Explorer. Now, highlight Internet Explorer and Click Add/ Remove.
6.Go to the location where you saved the newly downloaded IE and double click to install it. Follow the installation wizard.