I was in an advanced training class recently where several participants had problems completing the fairly complex hands-on exercises. Most examined the error messages carefully, re-read the instructions and solved the problem. But a few became irritated, read the instruction poorly, skipped parts, made unconsidered changes to their environment, and soon became helplessly stuck.
Getting angry at the computer, the software, the course material and the instructor does not help. Instead, it degrades your reasoning skills, which lead to you making more errors, which makes you more angry.
You need to be aware of how you feel. If you feel irritated at the computer, stand up and take a break. Once you have calmed down, your tunnel vision dissipates and you can find the solution.