temporary Word files never deleted

I have used CCleaner contentedly every day, till yesterday I changed my Folder Options to show hidden files and folders. I saw lots of files beginning ~$ , and lots of files beginning ~WRL with a tmp extension. Some of them dated back till before CCleaner was installed. I thought these were temporary files created by Word for each working session. I thought CCleaner was supposed to delete these. What can I do about this? I'd be grateful for some help.