All you need to do is change the default app. Click the Start button, Settings, in Search, type in default apps. Scroll to the bottom click on Choose default apps by file type, then scroll down the .pdf and change it to Acrobat Reader DC. I believe that is what you are using.
Or you can right click on any PDF file and select 'Open With', then follow the steps in this post (There are pictures there):
That will reassociate all PDF files back to Acrobat and change all the PDF Icons back. (You should need to but sometimes it takes arestart before they change).
You will need to do similar for Windows live mail, TwistedMetal's method may be better for that.
I assume that Live Mail was associated with Outlook? If so then you have to reassociate that Icon back to Outlook.
That should then leave you with CCleaner icons only for CCleaner itself and for the CCleaner browser.
(It was installing the CCleaner Browser as the default browser that caused the changes).
If your desktop shortcut icons have changed to look like the CCleaner icons it is because you have some how installed the "CCleaner Browser" while using CCleaner.
If you want your icons to revert back to their previous appearance you have to uninstall CCleaner Browser. If you have windows 7, you click on the start button, then click on the control panel button, then click on Programs/uninstall a program. Next, find "CCleaner browser" in the list of programs , left click on it and when uninstall appears click that.