Poor acquisitions and investments. Few of Microsoft’s acquisitions were successful and brought not just revenues and products but new skills and competencies to the company. Massive, LinkExchange, WebTV, Danger are just few examples of multimillion acquisitions made by Microsoft but soon shut down or divested
Dependence on hardware manufacturers. Microsoft is a giant software corporation but it does not produce its own hardware and depends on computer hardware manufacturers to develop products that run Windows OS. If cheap and popular alternative OS would appear, hardware manufacturers may simple choose the alternative and Microsoft could do little to change the situation.
Open source projects. Many new open source projects are coming to the market and some of them became quite successful, such as new Linux OS and Open Source Office. Open source projects are free and so they can become an alternative to expensive Microsoft’s products.