Hello! I understand you're having trouble registering again after losing your original install of the RepeaterBook app. To help you best, could you share a bit more about what happens when you try to register? For example, are you stuck on a certain screen, seeing an error message, or unable to find the registration option?

Meanwhile, here’s a step-by-step approach to get you started:

1. Complete Removal: First, make sure the RepeaterBook app is fully removed from your Windows system. Since you’re on Windows 10 with a WebKit browser, double-check that the app and all associated files are deleted to avoid conflicts.

2. Reinstall Fresh: Download and install the latest version of the RepeaterBook app from the official source or app store again.

3. Account Issues: If the problem relates to your account—such as forgotten credentials or password—try resetting your password via the RepeaterBook password reset page.

4. Register/New Account: Start the registration process anew in the app. If it says your email or username is already in use, it means your original registration still exists on their server, so logging in with your credentials or resetting the password is the way to proceed.

5. Check Connectivity: Though rare, ensure your internet connection is stable since the registration process requires connecting to RepeaterBook’s servers.

If you could tell me exactly where you are stuck or what error shows up, I can guide you with more targeted steps or troubleshoot advanced issues such as account recovery or server hiccups.

Are you currently trying to register a new account or log into an existing one?