To get back on line here.
1.CCleaner has an Option to enable Old prefetch files to be cleared. It does
not have to be checked/ticked , if you are in doubt.
2.Polonus said :
"...You must create a possibility to always go back on your tracks and undo what you apparently have miscalculated."
"...Who is the expert. He is the guy who really made all the mistakes he could in a very narrow field, and learnt from this."
I like this idea of learning through your mistakes, not that causing errors to your system is something you want to do, but when you do , and understand why, you wont make the same mistake twice.
I believe it's called the Empirical Method, from which all knowledge is gained. Our science today would not be alive if it wasn't for trial and error.
The subject of CCleaner performing a task which may slowdown or even disable performance is stupid. it's a user choice option. I'm glad I raised this issue, as the subject of prefetching has been explored . The Term has been around in a different instance before windows XP, as an optional setting for hard drive performance in older versions of windows, or maybe I'm thinking of BIOS settings.
However, User choice, having a Good System Backup, and
IF IN DOUBT, DON'T, are the dynamics to consider here, in my opinion.