http://www.liutilities.com/products/wintaskspro/processlibrary/iexplore/

This site can run a scan to determine if the iexplore.exe is the right one or not.

But your 'memory' warning may mean that you are running more programs than your RAM can support. You can easily add RAM to your PC. Also, clear out the 'Temporary Internet Files' folder. You can also allot more of your HD for 'virtual memory' to suppliment the RAM that you have.