Raise your hand and wait for the proctor to come to you. In most cases, computer issues are minor and can be fixed in a matter of seconds. If there is a larger issue that affects your exam, the Pearson VUE proctor will create an incident report for further investigation.
The online proctor will be aware of any computer or other issues that occur during your exam, and will take steps to immediately correct these. It is critical that you test your computer for proper hardware and software prior to registering for an exam.