verdy_p

"CCleaner526.exe /debug" or "CCleaner526.exe /DEBUG" has absolutely no effect (even when started from an admin comment line), there's no log file created anywhere, I just see a notification saying it is not compatible with my system. All version up to 5.25 were installing or updating without problem. Version 5.26 is no longer compatible with Windows 10 (64-bit version) official release ! The CCleaner instlaler was visibly incorrectly compiled (or compiled on an unsupported version of the Windows SDK, or only partly rebuilt instead of after a "make clean": the installer has evident problems of incorrect structures sizes when it calls the Windows API, probably caused by confusing 32-bit and 64-bit compiled modules, or mixing C/C++ headers from different SDK versions)

And I have an official version of Windows 10, official French localisation, running version 1607 (build 14393.693.) Unistalling completely and reinstalling this update does not work: your version check refuses the installation. Installing the revious version CCleaner 5.25 instead of 5.26 works without problem. The problem is in your installer which does not even attempt to installa anything and rejects my system version without copying anything (and without even creating any debugging log anywhere: nothing in CCleaner install folder, nothing in %TEMP%, nothing in Windows\Temp, nothing in Windows event viewer. My opinion is that the installer attempts to use an incompatible/unsupported Windows API to make its system version check, and fails to link to it, or passes some invalid parameter (e.g. wrong buffer size for results, or assumption about this size: it was probably compield with an incorrect version of the SDK, or not fully rebuilt from sources and now the installer mixes some .obj/.lib files compiled from another SDK version and some others with a new SDK update where some system structures are now extended). Note that this is concommitent with the recent Windows update and the apparition of a new SDK! You have probably compiled your installer with this new SDK (for test only, for for use in releases). Please rebuild your installer with some "make clean". I'm sure it is incorrectly compiled: using a DDK investigation tool, I clearly see that the installer makes false assumptions about system structure sizes needed and it gets an error because your allocated structure is too small to match the version you want to check !

Here is a screen snapshot under Vista (in 8-bit PNG format)

I now frequently get a strange error while trying to defragment the disk. The doalog displays (actually in French, but I give a translation here) "Defragmentation stops because of insufficient disk space". This is quite traoublesome, because there is ample enough free space on disk (more than 40 GB). I ran chkdsk, and there's no error. (note: there's no fragmented file when this occurs, only minor fragmentation of free space, with "0%" fragmentation statistics displayed) This occurs when the disk is almost completely defragmented, apparently it tries to fill in some very small free gap, and cannot fit any file in it, or Defraggler incorrectly computes the space needed to move a file there. It looks like this is a bug when trying to compute the space needed to perform a file move in a small free gap. I think this can occur with sparse files, or some compressed file, but the dialog provides no debugging info about which file caused that error. Is there a way to enable some debugging logging (in a log file or in the system event viewer?) when such error dialog occurs, in some hidden option that can be set in "Defraggler.ini" or in the registry?