The issue you are facing can be due to the add-on or third party extensions that loads with Internet explorer fails to work and then ultimately crashes the browser. The add-on gets attached to browser through many channels like when you install some applications e.g toolbars, popup blocker software or any software that places its icon in internet explorer.This issue can also be due to spyware/malware on the machine.
In order to use a workaround for internet explorer add-in, try to disable add-on one by one within Internet explorer properties and then test the browser performance. Also you can uncheck "Enable Third party browser extension" under the advanced tab of Internet Explorer properties.
In case above mentioned steps do not help, try to download "Spybot" from internet and scan the computer for any spyware or malware.
In case you still face this issue, please let me know and I will assist you further.