AVG Cache isn't being deleted on my PC

I have the AVG PC TuneUp software and when I click the "Free Up Space" tool and get into the cache portion, it shows an obscene amount that doesn't disappear after it goes through the "cleaning" process. How do I fix this issue?

Hello Warren,

We are sorry for the inconvenience caused.
The total number of files shown for free up space by AVG PC Tuneup also includes the file of windows operating system.
Removing such files will lead some problem for your PC or functions of windows features.
So, such files will not be removed by PC Tuneup whereas the recommended files will alone will be removed.