Hi,
1. When was the last time it was working fine?
2. Which version of Internet Explorer is installed on the computer?
3. Have you made any recent software or hardware changes on the computer?
Method 1:
I would suggest you to run the Fixit from the link mentioned below and check.
Fix Internet Explorer add-on problems when IE hangs or freezes
http://support.microsoft.com/mats/ie_freezes_or_crashes/en-us
Check if the issue occurs, if it does proceed to method 2.
Method 2:
Follow the steps from the link mentioned below and check
Tips for solving problems when Internet Explorer crashes or stops working
http://windows.microsoft.com/en-US/windows7/tips-for-solving-problems-with-internet-explorer
**Note:**Resetting Internet Explorer is not reversible. After a reset, all previous settings are lost and can't be recovered. Rather than resetting everything, you might want to reset specific settings in the Internet Options dialog box or delete your webpage history.
Note: There is a chance of data loss if any files are infected and which may be deleted in the clean up process.
Hope this helps and keep us posted if you need further assistance.