GreenJelly

Did the same thing, ccleaner totally destroyed my machine. Right after running it, no apps would run. Then I restarted and found a machine that wouldn't boot. Had to use a partition magic boot disk I keep to format my SSD and harddrive to reinstall. I tried to restart the windows installation and regardless of what options I pick, restart would fail. Repair also failed. Not too happy with Windows 10 either.

Ran a partition magic boot disk and formatted the hard drive. Now the Windows 10 disk boots without problem. Very strange. 3rd Install of Windows 10 since release. I am finding it Highly unstable, with applications claiming support but also full of issues. Information on Google or Bing is very hard to find. I can not recommend Windows 10 to anybody but the most tech savvy individuals. This has been painful and if I didn't know what I was doing, this latest issues created by ccleaner would have ended with a potential change of hard drives or bricking my pc. I am NOT happy. Don't claim support if your product destroys the system it runs on.

I ran the cleaner, checked the option to remove the windows.Old files from a previous install. When it was done deleting files and my system restore files applications wouldn't run. On a restart windows wouldn't boot. Repair would fail. Restart fail. The DVD I created wont boot so now I am re-downloading it and going to try and burn it on another disk. Booted off Windows 7, got a "Boot Selection failed because a required device is inaccessible" on the installation. Im going to keep triing, and Hopefully the new disk will boot. If not I am going to Install Windows 7 and Abandon Windows 10 for awhile. I have always relied on CCleaner and found it to solve, not create problems. Unfortunately this is not the case and I can't recommend anyone run it on a windows 10 machine.