IDC forecasters are pointing to a drop in worldwide PC shipments as emerging markets lose interest in favour of newer ways of connecting to the internet.
The research company say that the industry will never regain its peaks that it saw in 2011 when over 359m units were shipped worldwide.
The IDC say that total shipments will fall by 9.7% this year compared to 2012, and will continue to drift down until 2017.
Key competitors responsible for the drop are smartphones and tablets in emerging markets, together with economic troubles in both the West and the emerging markets.
The research also said that China will see double-digit declines in shipments as both first-time and upgrading users turn to tablets and smartphones.
This spells bad news for PC manufacturers like Dell and HP, which have not been able to break into the mobile markets with any success comparable to their counterparts. The effect is more marked in the consumer market, which is down 20% year-on-year in some areas, than the business market, where companies have begun to install Windows 7 on a large scale ahead of the end of support for Windows XP - first released in 2001 - next April.
The dropoff could have long-term implications for Microsoft's Windows business, formerly one of its most valuable monopolies.
For consumers, the rise of tablets has produced a new refresh cycle which directly subtracts from PC makers' revenues.
"The new forecast reflects not only a continued expansion of mobile device options at the expense of PCs, but also marked the cessation of emerging market growth that the industry had come to rely on in recent years," IDC said.
But the rapid rise especially of tablets has eaten into that - so that it now reckons this year's total will hit 315.4m, a 28% cut from that older forecast.
In June 2011, the IDC was forecasting that by 2015 total world PC shipments would rise to 541.5m. Now, it reckons the total will instead be 318.2m - a 41% cut on its earlier expectation.
The figures include desktop, netbook, and other laptops including ultrabooks and "convertibles" which can act as a tablet and PC, but don't include purely handheld devices or tablets such as the iPad.