I think you are being a little premature. All iMacs have hard drives by default.
http://store.apple.com/us/buy-mac/imac?product=ME086LL/A&ste...
http://store.apple.com/us/buy-mac/imac?product=ME087LL/A&ste...
http://store.apple.com/us/buy-mac/imac?product=ME088LL/A&ste...
http://store.apple.com/us/buy-mac/imac?product=ME089LL/A&ste...
http://appleinsider.com/articles/14/01/09/apples-domestic-ma...
I did find articles from early 2012 calling Apple the biggest but that was of course based on iPads almost entirely. For example [1] has some figures from then, 5.2 million macs to over 10 million units each from HP, Lenovo and Dell.
[0] http://www.mercurynews.com/ci_23637017/hewlett-packard-loses...
[1] http://appleinsider.com/articles/12/01/24/apple_now_largest_...
HP/Lenovo have the top two spots, they're selling tens of millions per quarter. Apple barely breaks 5 million.
Apple doesn't have great business nor governmental support, which eliminates them from being considered at thousands of companies.
The revenue Dell pulled from their consumer division (which includes desktop/laptops/thin-clients/mobile devices and so on) is $8.9 billion.
> End User Computing revenue was $8.9 billion in the quarter, a 9 percent decrease. Operating income for the quarter was $224 million, a 65 percent decrease. Dell desktop and thin-client revenue declined 2 percent, mobility revenue declined 16 percent, and software from third parties and peripherals revenue declined 6 percent.
Source: http://www.businesswire.com/news/home/20130516006383/en/Dell...
In Apple's '14 Q1 report, their Mac revenue was $6.4 billion. iPad: $11.4B and iPhone $32B for the total of ~$50B.