Missing Internet Explorer

Hello,

I use internet explorer. However after doing a performance "clean up" of my system the icon and my internet explorer icon disappeared. I used control panel/performance & maintenance and checked to free up space. My system calculated space I could save. I read each description and chose only those options that said would not delete files. Well....

If I go to my Start Menu the only icon available is a globe. I click it: I get internet options/general (tab) with an option to select a home page. The address in the window is www.google.com but the button "use current" is not lit.

I got online through a "back door" and went to "tools" to select internet options. The home address remained www.google.com and the "use current" button was black. I clicked it; the "apply" button lit; I clicked it and clicked ok. Nothing changed.

I can get online but not through internet explorer anymore. I got online by clicking a link to the internet while troubleshooting.

My desktop icon, the icon in my start menu and the program under add or remove programs does not show internet explorer. I used it for years and only after the "clean up" did I lose it. Can I download it again - free?
What are my options please.