Thanks, but I still have some questions:
1.The example I mentioned above with picture (chrome version updated), it's safe to delete but not necessary, right?
2.What's a good timing/situation to run registry cleaner?
3.If I do not need to clean registry, then what about file cleaning?
I only clean what I know exactly (I am still on Windows 7 though), because I don't want to have oversized temporarily files or tons of error reports generated several years ago. Recently I have read some articles indicate that we should not use file cleaning tools such as CCleaner, they said it is very risky to clean your system files especially on Windows 10.