I get 4 strange files msdart.dll why?

[jfodonnell]

When l oprn Outlook e-mail. Four strange files come up which l delete as they
seem to have no purpose. cicerovtwindframe.outlook.exe;
htmltooltip.outlook.exe;Outlookhtmlmenu,outlook.exe; and last one is
repeated. What is their purpose and if no purpose how do l get rid of them