Does cleaning the old prefetch data and font cache via Ccleaner help or hinder ?
There's no reason to clear prefetch data.
Quoting from my Lifehacker article on the subject:
The Prefetch feature in Windows XP caches parts of applications that
you frequently use and tries to optimize the loading process to speed
up application start time, so when a number of sites started
suggesting that you clean it out regularly to speed up boot time it
seemed like good advice... but sadly that's not the case, as pointed
out by many Lifehacker commenters.
The Prefetch feature is actually used as a sort of index, to tell
Windows which parts of an application should be loaded into memory in
which order to speed up application load time, but Windows doesn't use
the information unless it's actually starting an application. There's
also a limit of 128 files that can be stored in the prefetch folder at
any point, and Windows cleans out the folder automatically, removing
information for applications that haven't been run as frequently.
Not only that, but a well-written defrag utility will use the prefetch
information to optimize the position of the files on the disk,
speeding up access even further.
Windows expert Ed Bott explains it: The .pf files don't get used at
all until you run a program. What actually happens when you click an
icon is that Windows uses the information in the Prefetch folder to
decide which program segments to load and in what order to load those
Thanks Lowell for that zapping fast reply.
By default, they are not enabled and I was wondering why.
Is there a 'thread solved' button anywhere in the new avatar ?
No 'Solved' button yet. It was recommended to put (Solved) in front of the title.
Danke whs. As smart as always.
In general, any kind of caching or prefetching should be left alone, as most programs (including operating systems and web browsers) are designed by reasonably competent people, who put those things in deliberately to improve performance.
There are some special cases that revolve around privacy, corrupted caches, and cache behavior that's known to be incorrect (such as really old versions of Internet Explorer that let the cache get so big that it literally took longer to search through than it did to retrieve the page again), but in general, caching is done for your own good, and disabling it will slow your system down.
The font cache is an example of this. The only time you'd clear it is when you observe something obviously attributed to brokenness, such as fonts not displaying correctly, or obvious hangups with font loading. Same with the icon cache - you know it's time to rebuild it when half the icons on your desktop are not displaying correctly, or flashing generic "document" icons for 30 seconds as the desktop's loading.
Beyond that, while CCleaner as a whole is useful, many of the functions in CCleaner are no better than placebos if not actively harmful to performance. Know what the tool you are using is supposed to do and why you are doing it, lest you realize in the middle of shooting yourself in the foot that the tool you are holding is a gun.
I was looking at your decussion on old prefetch files and geeks discussion mentioned that there is only supposed to be room for 128 files and that the computer is supposed to keep old unused files cleared out. Well my prefetch folder has 146 files and it does not seem to be clearing them out as I go in occasionally and don't see any changes. I also deleted some old files associated with avg secure search and it did not seem to hurt as I deleted all othe avg stuff. dave