Microsoft has reported a 22% fall in quarterly profits after waiting for the release of its Windows 8 operating system and its latest version of Office.Net profit for the three months to September fell to £2.79 billion ($4.47 billion), from £3.58 billion a year earlier and consequently they missed shareholder expectations.
Total revenues fell 8% to £10 billion.
PC sales fell as consumers either put off new purchases in a tight economy or opted for tablet devices instead.
Microsoft deferred a total of £850 million of revenue, which it will regain in the following quarter.
This included £489 million in licence fees for PCs pre-loaded with Windows 8, because it cannot recognise the revenue until the units go on sale on 26 October.
It also deferred £240 million for PCs that shipped with Windows 7 but are eligible for a £9.50 upgrade to Windows 8, and £118 million for PCs that shipped with the new version of Office or are eligible for an upgrade.
Microsoft shares fell 3% in extended trading.