Mike...

Definitely start with Cookies to Keep. I've been using Edge Dev since it became available, it's very stable and I'm using it as main browser. That's the feature I miss most.

I have the same issue. Running the installer shows the extracting part and then nothing, no errors. I turned off Kaspersky Internet Security. Installer runs just fine... I think Kaspersky does not like the new optional bundled software... see capture. I tried turning off some individual settings in Kaspersky (Installation Assistant), but no luck so far.

Yep, that did the trick for me as well. Blocking the installer based on the filename is not very effective on the part of MS. Why it is blocking CCleaner at all, I do not know.

The new update to CCleaner fixes this issue, it now maximizes properly.

The issue I previously reported with the maximized window not really being maximized depends on the Windows setting Auto-hide the taskbar. With the setting enabled, issue. With the setting disabled, no issue. The question is now, is this a Windows 10 issue or a CCleaner one?

Just thought I'd revisit this thread. There is a new maximize issue in CCleaner 5.09.5343. See screen shot. There is blank space at the left, bottom and right of the "maximized" window. In the background there is a maximized Notepad. If I manually try to resize CCleaner, I cannot make it the entire width of the screen either. This last part happens with some other applications as well, for example Windows Media Player... I've also noticed that the smaller icon at the very top left is still somewhat pixelated, the rest looks great with Windows 10's new scaling, set at 125%. Though the installer has the fuzzy text issue, which doesn't really bother me, but is apparently a hot topic for Windows 10. Finally, I noticed the title bar now uses native elements for the buttons, this is great! Can't wait for a future Windows 10 update to give me the option to color the title bar...

After having upgraded to Windows 10, I decided to revisit this topic. I noticed how similar CCleaner's top looks like the Windows 10 style. Surely it's time to use native Windows 10 elements instead of CCleaner's own? The Windows 10 elements look superior to CCleaner's. Although in general Windows 10 needs some more color at the top and a thicker window border.

Two small things I've noticed that could do with a graphics update. The installer itself also shows a slightly pixelated pear, but then we're really nitpicking.

Indeed. Still prefer the v4 look and feel, but with this DPI update v5 is tolerable.

The maximized window isn't really maximized. I can see my desktop wallpaper at the bottom. Compare to Notepad, where I can not see part of the wallpaper, just part of the auto-hiding taskbar: vs. CCleaner should just use native windows elements and not its own custom elements. On a side note, certain visual elements are still not DPI aware, like v4. See the pixelated check marks and icons. Guess I'll be using v4 for a little while longer.

In logic, that's called a fallacy.

Here's a comparison of the GUI concerning DPI scaling: As you can see, there are some minor scaling issues in the old GUI, especially with the smallest icons, like System and at the top left. But the rest and for example the check boxes look perfect. Then take a look at the new GUI and the graphics look awful, it's just the text that looks okay. How can anyone call that an improvement?

FYI, I use Windows 8.1 Pro. Um, yeah... this is not an improvement. I don't like the custom title bar. Why not just use systems colors and system buttons? If CCleaner is maximized, you cannot get to the auto-hidden taskbar anymore. Overall the graphics quality is poor. I use a higher DPI setting (125% on a 23.7" monitor with full HD resolution) and all the icons and even checkboxes look very poor. Most software developers know how to handle this by now, Piriform does not. Please address the above issues, I'll be using version 4 in the mean time.

Good initial question. I'm currently investigating a cookie issue and I'm curious about index.dat in the following folder: "%AppData%\Microsoft\Windows\Cookies". When I right-click the file and choose properties, the Created Date is January 19 (last time I installed Windows anew), now, I use CCleaner all the time and have index.dat checked and usually certain cookies to keep. Not sure how that all works, but if the Index.dat there would really be deleted, I would surely see a more recent Created Date... No?! And when I open the index.dat file with Notepad I see stuff I really shouldn't be seeing...

Done, thanks.