It should be one of the most exciting periods in years for people looking to buy new PCs, with a new version of Windows on sale and shelves full of slick touch-screen devices to run it.

But not only have the new offerings failed to stop the downward slide in PC shipments that has been going on for the last year, they appear to have made it worse.

On Wednesday, the research firm IDC reported that worldwide PC shipments declined 13.9 percent during the first three months of the year compared with the same period a year earlier.

To put those numbers into perspective, that is the most severe decline in the PC market since IDC began tracking the business almost two decades ago and almost double the rate of decline that the firm was expecting for the quarter.