I can't delete something on iexplorer why?

Why are you using IE?

Use a decent browser like Google Chrome.

Go to control panel and go to programs and features scroll down to Minecraft and highlight it then uninstall it. After you remove from your computer than you may have to reboot(restart) your computer. Now for your computer when you go online and in your search bar type your windows and download internet explorer 9,10 or 11 so if you have a windows xp or vista internet explorer 9. But if you have windows 7 or 8.0 I recommend windows 10 now for internet explorer 11 I don't recommend that because Microsoft does not have that internet explorer perfected yet so there's problems with it. Do your updates after you are done installing so if the computer ask you to reboot go ahead and reboot then go to control panel hit the updates and to the right it will say check for updates hit that and go ahead and install them again it will ask you to reboot. Now for your default always use internet explorer this way iexplore will work for you.