"You get a call from a user saying they logged on and were working fine, but now they can no longer access the web, print documents or send e-mail. What would you do?"
After hearing everything from running diagnostic tests to rebooting the computer, not one of these certificate-holding, college graduate applicants offered up the obvious:
Check the cable connections.
I thought of this today when someone I know freaked out over "losing" a ton of documents on their computer. The document files are/were stored on an external USB hard drive. The cable had come unplugged, but the system cache still showed the drive as being active. Thankfully, it was cured by just re-attaching the connector.