Software giant Microsoft is suing UK electronics retailer Comet after it became apparent the store chain allegedly created, then sold 94,000 unauthorized "recovery" CDs to customers for Windows XP and Vista operating systems, between March 2008 and December 2009.

According to the Guardian newspaper, Comet disputes the claims saying it acted in the best interests of its customers. The fiasco happened after Microsoft stopped supplying recovery discs with new computers. They say the CDs were sold to existing customers so they had a means to recover their Windows operating system in the case of hard disk failure.

"As detailed in the complaint filed today, Comet produced and sold thousands of counterfeit Windows CDs to unsuspecting customers in the United Kingdom," said Microsoft lawyer David Finn, in a statement to the newspaper. "Comet's actions were unfair to customers. We expect better from retailers of Microsoft products --- and our customers deserve better, too."

Microsoft has advised anyone who has purchased the discs from Comet to check their "How to Tell" page if they are concerned whether the disc is genuine or not. The webpage offers advice and steps required to verify the media is genuine.

Comet admits producing the CDs at a factory in Hampshire and then selling them across its entire chain of stores. The retailer believes that those actions did not infringe on Microsoft's intellectual property.  "Comet firmly believes that it acted in the very best interests of its customers," a spokesperson said in a statement.

"It believes its customers had been adversely affected by the decision to stop supplying recovery discs with each new Microsoft operating system based computer." They believe they have a solid defence and will vigorously oppose the lawsuit.