Hi. I need to know historic & projected quantity numbers for PC's sold
in the US & world wide. Mostly interested in years 2003 and
projections to 2009 or 2010. Additional breakout would show portion to
business v. home use.

Hello jallen:

Thanks for the interesting question. Of course, these types of figures
(even when they're historical) tend to differ depending on who's
counting. I have tried to collect figures from the most respected
consulting firm in this area. I've relied heavily on IDC data, as they
are the most reliable source for such stats.

Let's start with worldwide quantities of PCs sold in 2003 and 2004:

PC Sales Strong in 2004
URL: http://www.pcworld.com/news/article/0,aid,119347,00.asp
Quote: "PC vendors shipped 177.5 million units during 2004, up 14.7
percent from the 154.7 million units shipped in 2003."

Market analyzer lowers global PC market forecast for 2005
URL: http://english.sina.com/business/1/2005/0324/25352.html
Quote: "...compared to about 178 million in 2004, according to a
revised forecast released by IT market researcher IDC on Wednesday."

Now, for future worldwide forcasts, I was able to find the following:

Market analyzer lowers global PC market forecast for 2005
URL: http://english.sina.com/business/1/2005/0324/25352.html
Quote: "Total PC shipments are expected to reach 195.4 million in 2005
on growth of 9.7 percent, with shipment value growing by 5.3 percent
to 209 billion US dollars. Shipments are projected to reach 273
million in 2009 with a value of 245 billion dollars."

In fact, there's a really nice table at the following website that
lists sales and projections for 2002 - 2006, broken down by
consumer/commercial AND broken down by US and worldwide!

IDC Lowers Short Term PC Shipments Forecast, but Claims Solid Long-Term Growth.
URL: http://www.xbitlabs.com/news/other/display/20050328041118.html
Note: Table is half-way down the page. Have a look!
 
So, If we were to assume a constant level of growth for 2007, 2008,
and 2009, we could summarize the worldwide totals data as follows:

(in millions of units)
2002 - 138.2
2003 - 154.8
2004 - 178.1
2005 - 195.4 *
2006 - 212.2 * 
2007 - 230   * @
2008 - 251   * @ 
2009 - 273   *

* - IDC projections
@ - calculated from 2006 ans 2009 projections, assuming even growth rate

It is probably not a good idea to make similar extrapolations about
the US or commercial/consumer sectors, since their growth rates can
differ dramatically year to year.

Search Strategy (on Google):
* "PC market" global OR worldwide million
* "PC market" million 
* "PC market" million 2003
* "PC market" million 2006
* "PC market" 2009 US million IDC

If you need further clarification on this answer, please let me know
before you rate it. I'm happy to work with you further on this, if you
need more details.

websearcher

Excellent. Just what I needed. Thanks.