I have MICROSOFT Windows XP Professional Version 2002. An Intell Pentium processor with 448 MHz, 320 MB of Ram. The problem has been random but when I try to open programs on the internet (example, delmarlearning for school) I get an error message "Internet Explorer has encountered a problem and needs to close". At the bottom are two options, "Send error report" "Don't send". I did a defrag last night and that didn't help.......Why would you think defragging would do anything??

I'm not sure what you mean by "open programs on the internet". Can you please explain? And see if the same thing happens with another browser (ie, Firefox, Opera, etc).You probably mean a student platform on your browser by 'internet programs', mm?
I have one myself. It's one of those college platforms where users LOG onto.
I would look into what Delmar is made of. Perhaps you need to INSTALL Java for some plugins.

Also, try a DIFFERENT browser. =)"Internet Explorer has encountered a problem and needs to close"
I'd travel to our malware FORUM for health check.

You need more RAM too.