Windows – Clipboard stopped working

Check out https://stackoverflow.com/questions/621577/clipboard-event-c

I don't think you can do more than there is available with the API, but this should be helpful enough to roll up your own Clipboard Monitor or request someone from that question to provide you theirs. Monitoring and showing the contents of the clipboard each time can be helpful whether to decide if something third-party is messing with your clipboard, from there you will have to identify the culprit by eliminating processes or something like that.

The answerer left an update in the comments:

Update: For some reason, this problem went away on its own. I'm able to use Ditto as it used to work, collecting everything that I copy. This is kind of frustrating, as it doesn't address the original issue. – Bassam Mar 1 at 18:03

Here are some suggestions if you might experience this problem as well:

1. Try to run with elevated permissions and a less locked down UAC.

2. Update your Windows and software.

3. Create a new user profile to see whether it happens there.

4. Remove automatically starting entries, as another start-up program might perhaps interfere...