Diagnose an IT problem I have not been able to fix

Help me diagnose an IT problem I have not been able to fix. Symptom: [WHAT the user sees, exact error message or code] Device and environment: [OS and version, app and version, device model, on-site or remote, network type] Scope: [one user / several users / one location / everyone] When it started and what changed around then: [updates, new software, password change, moves] What I already tried and the result: [LIST] Relevant logs or screenshots described: [Event Viewer, app logs, etc. - optional] Steps: 1. Restate the problem precisely and say what the scope tells us (user, device, network, or service level). 2. List the 3-6 most likely causes, ranked, with the evidence for and against each. 3. For each, give the next test to confirm or rule it out: exact commands, settings paths, or log locations, starting with quick, non-destructive checks. 4. Note anything I tried that may have hidden the real cause. 5. Say when to stop and escalate, and what to include in the escalation. Rules: - Warn me before any step that can lose data, reset a profile, or affect other users, and tell me to back up first. - If you are not sure a command or menu path exists in my version, say so. - Do not ask for the user's password; suggest ways to test without it. Return: likely causes table (Cause | Evidence | Next test | Risk of test), then a step-by-step test sequence and a short ticket note of what was done.