DSG, the group behind Currys and PC World, has issued a profit warning, stating that poor sales of Vista could see its profits slashed by around £20 million.
Apparently the group had predicted a surge of uptake for Microsoft's new operating system, with customers keen to upgrade their hardware.
Expecting a sales spike tens of thousands of extra laptops were ordered, but the expected demand did not materialise so the group were forced to offer the hardware at a discount.
"We thought many more customers than transpired would want to change their existing hardware", DSG's Finance Director Kevin O'Byrne told the Guardian.
He blamed Microsoft for the poor uptake of the new system and said he was "disappointed with the lack of promotional support".