Unsigned wrote...
So that I know, what causes Cyclic Redundancy? Virus? Age?
Uh, 'Cyclic Redundancy' isn't a problem. Cyclic Redundancy CHECK is a method of making sure your data hasn't unexpectedly changed. (eg. corruption)
Your question should be reworded as "What causes data corruption?", to which many factors such as power fluctuations, poor hardware construction, and bad software could be causes.