Alice,
on this page; https://www.piriform.com/ccleaner/builds you'll see three download options. (actually right now, at time of writing there are only two, the Slim will be there soon)
there is the normal installer, the Slim build and the Portable build.
the normal installer has the CCleaner program plus a bundled offering of Chrome, this keeps the standard version free.
the Slim build is the standard installer but without the Chrome offering. but it gets delayed by about a week after any new version is released before you are able to download it.
lastly, the Portable build, same program as the standard, but again without the Chrome offering and it doesn't actually get,. or need, installing. you just run it from where you want (once unzipped).
if you are still on v5.25, then get v5.26, but I doubt it will help your IE issues.
you can search on the forums for other threads covering this issue but to boil it down, Microsoft has changed how it stores its temporary internet files, and so Piriform has had to change how it clean said files.
now users are reporting either slow IE cleaning, lack of IE cleaning or IE skipped cleaning.
if yours is the slow issue, sadly it may be a case of it is what it is, until Microsoft or Piriform changes things.
don't forget, you always clean IE crap from within IE itself.
then there's solutions like only running IE in private mode, so crap never accumulates, or getting the Pro version of CC and have it clean IE as you close IE.
or maybe even ditch IE in lieu of another browser, say Chrome or Firefox.