If you are unable to log in to the trademark registration system after changing your computer, there may be the following situations:

1. The username or password you entered is incorrect: please check the username and password you entered. The password is correct and no characters are missing or entered incorrectly. If you forget your password, you can reset it through the password reset function provided by the trademark registration system.

2. System error: There may be some system errors in the trademark registration system, resulting in the inability to log in. You can try to log in to the system multiple times, or contact the customer service staff of the trademark registration agency for help.

3. Computer configuration problems: After changing the computer, some computer configuration problems may occur, resulting in the inability to log in to the trademark registration system. Please make sure your computer is properly connected to the Internet and that your browser has the correct proxy server or firewall settings.

4. Browser problems: If the browser you are using is incompatible, you may be unable to log in to the trademark registration system. Please try another browser or adjust the browser mode to compatibility mode.

5. Soft certificate issue: If you need to use a soft certificate when logging into the trademark registration system, you may need to reinstall the soft certificate driver and download the soft certificate. You can try to uninstall the old version of the soft certificate driver, then re-download and install the new soft certificate driver, and download the new soft certificate.

If you have tried the above methods and still cannot log in to the trademark registration system, it is recommended that you contact the customer service staff of the trademark registration agency for help so that the problem can be solved in a timely manner.