I've been using this product for years. I'm using a licensed version and suddenly it will not open. It uses 100% of my hard drive. Never had this problem before. Still running windows 10 64 bit but who knows what they have updated. Any input would be appreciated.
A few simple things to try first; restart the computer via the Start menu and see if this allows it to run normally. You could also try uninstalling the software, restarting the computer fully, and then installing the software again.
You can look up your license information and download link for the software from our website here: https://www.ccleaner.com/support/license-lookup
If the issue still occurs after this, then I would recommend running CCleaner in Debug mode, as described here: https://support.piriform.com/hc/en-us/articles/360048363751 and send this log, along with any other observations you may have made, to our support team via the Contact Us form located here: https://support.piriform.com/hc/en-us/requests/new?ticket_form_id=86507 or by emailing support@ccleaner.com directly and we'll be happy to look into the matter further.