What is the best way to respond if a customer says that their computer is suddenly running really slowly?

Ask the customer what they were doing when it slowed down and if they have recently installed anything new to their system. The best response would be to ask the customer what they were doing when it slowed down and if they have recently installed anything new to their system.

It is never best to let a customer know about the worst case scenario before examining their computer. this can cause a customer to panic unnecessarily. It is best to stay away from using computer jargon with a customer. telling them you will just need to defrag their hard drive and wipe their computer for spyware and malware may be confusing.