CSC is one of the largest outsourcing companies in the world and it is believed that the affected server was responsible for a wide range of tasks, including Internet traffic, extranet applications and database access for the CSC and some of its customers.
Cable & Wireless (C&W) told CW360 that the server's downtime lasted 36 hours. Problems began late on 19 September, after what C&W described as a "serious hardware failure".
A new server in C&W's Swindon data centre was brought online in the morning of 21 September.
There is, however, some confusion about the scale of the problem and the location of the affected server and data centre.
One customer's emergency response team was reportedly told the problem lay in hardware in one of C&W's data centres in the US.
C&W UK could not confirm this: "The only affected server I'm aware of is a small server in the UK which is not within in our main facility in Swindon," said a spokesman.
C&W would not say what the fault was, if any other customers were affected, or why it took 36 hours to rectify.
A customer who asked not to be named said, "[we] will be considering our SLA agreement to see if any financial compensation can be demanded from C&W."
C&W has 17 primary hosting centres around the world, with over 500,000 sq ft of hosting space. It also claims that its largest US hosting centre is able to process 700 million Web visitors in a single day.
C&W would not say which vendor supplied the affected hardware. However, C&W has a £350m, five-year deal with Compaq for joint hosting and application services for large corporations.