Windows does not boot after running CCleaner

Hi, I've been using CCleaner for years on several computers and it's been great. However, after today's running of registry of both Cleaner and Registry (I do it every couple od months), my computer does not start anymore. Windows gets stuck during the boot up period and then the screen goes black, I don't even get to the login screen. Anyone able to help me, please?

PS: No, no registry back-up was made... sadly.

if you had restore points turned on, you could try booting the PC into Advanced Startup Options mode.

turn the unit on, as it tries to start Windows, hold in the power button until it turns off.

repeat this until it says something like "entering repair mode" and it'll take you to the ASO screen.

click Troubleshoot, then Advanced, then System Restore.

What operating system?

Did you have any of the sdvanced options ticked for cleaning?