iexplore.exe is always running

I have the same problem with my PC. iexplore.exe is always running and reopens itself if I close it manually by ending the process in the task manager. There is also a search engine bug that I believe to be related. It will not allow me to click on links in search engines and it blocks access to most websites for fixing computer problems. (it will not, for example, allow me to download combofix). I managed to get combofix on the desktop by transferring it from another pc, but combofix will NOT run. I click on the icon and the hourglass comes up, it also shows in the procceses list, but there is no window open. I have followed directions and close all open programs and disabled AVIRA but I am at a loss here. I have a hard drive imaged from this one from about two months ago that I can swap out if I have to, but I would prefer to fix the problem if possible. Thanks in advance for any suggestions!