You could try download / install an alternative web browser, for example www.opera.com or www.firefox.com.
As for the IE problem you could try running it in 'Safe-Mode' with with no add-ons loaded.
To run in safe-mode, depending on your version of Windows try clicking 'Windows Start' then in the run/search box type "iexplore -extoff" and press OK.
If that works ok then it is most likely an add-on that is the problem but it should allow you to download and install another web browser type.