In the dropdown menu located in the Defrag button there should be a "clean temp files then defrag" or "CCleaner>Defrag". I feel this way because before you defrag you want to kill those wasteful temp files. Defraggler would have to detect if there is a CCleaner installation for this to work.

Not necessarily. CCleaner could be built into Defraggler, & it could run before defragging. It could be updated with each version of Defraggler! Having a built in version would eliminate the need for a check/download if they did not have it!

Not exactly logical since ccleaner could be installed any ware. There is no magic way of knowing where it's installed.

It's in the registry: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\ccleaner.exe

Yeh sorry i know that, I have moved the exe once or twice and it didn't update. Maybe it's just me.

I assume this entry is updated by the installer; so yeah if you just moved the exe this wouldn't get updated.

Similarly, if you only have the portable version deployed this entry wouldn't exist either, so going back to the OP you'd only want to offer ccleaner from defraggler if this entry was present. Haven't made up my mind yet whether or not I think this would be a good idea anyway!

You don't need to know where it is installed if it is built into defraggler. It would use relative paths.

I know about this from making my own portable apps.

I want to add my support for the idea of being able to run CCleaner before defrag (in fact I was going to suggest it myself), but the suggested user interface isn't sufficient.

The reason for running CCleaner first are both the make the defrag run faster (no need to defrag the files that you deleted), and to make it more effective (the files you actually use will be placed closer together, not separated by "junk" files that should be deleted.

The reason the suggested user interface, the addition to the drop down menu, is not sufficient is that it requires human intervention and thus wouldn't work with defrag calls that are the result of regularly scheduled defrags, i.e. those invoked by the automatic scheduling function. So, while the addition to the drop down menu would work for manual invocations of Defraggler and might be the best way of handling those, there should be a method chosen to invoke CCleaner that you can have run without requiring mouse clicks, etc. There are several ways this could be done, and I don't have a strong opinion on which way is best.

An alternative that would satisfy my requirements in this area is to build the automatic scheduling function into CCleaner. Then I could just have it scheduled a few minutes before the scheduled Defraggler run.

Also, as to whether CClearner should be "built-in" to Defragler, or the standard CCleaner should be called by Defragler is a choice best left to the developer. We should only care that it works, not what mechanism is used "under the covers" to make it work.

Thanks for your attention and for continually improving your products.

I second that...a "silent mode" option could be added to CC then DF could call it using the registry key before performing the defrag. When DF opened, it could turn the option on/off based on the existence of the key (and may be quick check with FileExists()).