Yes, burn IE5.01 to a CD, then install it on your g/f system.
You can not open MSOE.DLL, its not an executable, this is either "Object Embedding" or "Outlook Express" support dlls'. Which are library files.
If she had 5.01 on it and it kept crashing, and you put it back on, Its possible it could do the same thing again, you might consider IE5.5
IE is a BAD idea for a web browser by the way. If she has things messed up on the system. Just consider letting things be. Get a browser which is better.
You can use Firefox, and Thunderbird. Firefox being a web browser, Thunderbird being a email client.
http://www.mozilla.org/products/thunderbird/releases/
http://www.mozilla.org/products/firefox/
Firefox will be safer to run, less chances of scripting errors, less likleyhood of pop-ups. which can not be blocked with IE without thrid party apps. and the more apps you need to load the less RAM, Resources available, best to run a single app which support these features.