Indeed, I am currently using an old retail serial key at the moment, entered directly into version 5.56 which cheerfully auto-updated itself to 5.58. No keys were cancelled just because the licences had expired, and retail keys will work on the downloaded software. Periodically, we'll cancel keys that have been found to have been pirated. They tend not to work.Ĭancelled pirated keys. There are quite a few of these sold by third parties for too-good-to-be-true prices. The CCleaner licensing system is a bit old, clunky and temperamental - you need to enter a name, not an email address and it's case sensitive to the capitalisation it has on record for you.Ĭounterfeit keys. Putting the wrong information in the 'name' field. For customers who have purchased online, it is recommended that the serial key be copy-pasted from the email to avoid this.

The most common is a mistranscribed serial key - typing a '2' instead of a 'Z', etc.

On the broad topic of people saying that their serials don't work when entered into the product, there are a number of reasons why this can happen:

Most of the other matters have already been answered. This thread has quite a few different topics in it.

Ccleaner pro serial 2018