Troubleshooting

What information should I gather first?

Record what the user expected, what happened instead, the exact error and when it began. Check whether it affects one application, one device or several users. Use that scope to choose a topic-specific guide.

How should I test a possible fix?

Change one thing at a time and repeat the original task. Record the previous setting so an ineffective change can be reversed. Collect relevant system information or events when the cause remains unclear, instead of stacking several repairs without checking their results.