The error "application error instruction ###### reference memory #### could not be read" can be from a few different reasons, the worst possibility could be bad memory (RAM). My first question is how old is the computer and is that the original memory that was in it. Without more details of the error instruction # and memory # I cannot be more detailed.
To figure out if your RAM is going bad is not always easy. You can try a memory test, like the one here
Memtest86.com - Memory Diagnostic but there really is no ideal test for memory. When you try to troubleshoot memory though, is Internet Explorer the only program that is giving you that error or do you get the same error from other programs? You can also try a 'stress test' program like Prime95 or the enhanced version of that program at this site
Stress Prime 2004 . The stress test programs will probably take a number of hours to run, but if they come up with errors, it is a good chance that you have bad memory. The only other 'test' I can think of right now is actually removing some of the memory from the PC and seeing if still get the errors or not, and then taking out the other memory and putting the first back in and trying again, but I don't recommend this way for people who aren't good with computers.
Anyways, with such little information, my first guess is to check memory and easiest way is to start with a stress test.
If that doesn't help, please provide more information like the whole error including the memory address and error code as well as some information about your computer like what kind it is and what hardware. You may even be able to find information online about the error by doing a google search for the error code and memory location.
Please continue to post here with any more info and results of stress test and I'll do what I can to help. I know how frustrating computer problem can be, especially for someone not good with computers.