We can't update CCleaner v.64 on XP or Vista:
This means that v5.64 is the last version of CCleaner you can use on Windows XP or Vista.
If you try to update to a newer version of CCleaner, you won't be able to.
Windows XP, Vista, and online threats:
Like Microsoft, we recommend retiring your Windows XP or Vista computer and upgrading to a new one.
This is especially true if your computer is connected to the internet because XP and Vista no longer receive security updates, making them vulnerable to online threats.
If you’re using XP or Vista and have a question, you can contact our support team at firstname.lastname@example.org.