I worked for a series of computer companies (Vanstar, Inacom, Custom Edge, Compaq Direct, Compaq and finally HP) though I always worked at the same building and never quit or got hired... just companies kept buying one another and changing names.
I think Carla got something like $17,000,000 when the deal was closed to 'merge' Compaq with HP. There were many 'behind the scenes" reasons for the merger which included Vanstar/Inacom's customer base and HP aquiring Compaqs server line.
But, as with all mergers, 10,000 people were slated to be laid off because of the merger. Mostly sales offices which would be nearly duplicated with the merger. When I started, the people that built (and/or customized) the computers were knowledgable folks that were expected to know how to tear a comnputer down, troubleshoot it, and fix it with little help. Now, computers are made on an assembly line and I think they specifically seek out people with zero computer experience. You don't really need to be able to read and write to work in many positions now. Scary thing is, they cut about a third of the quality department as well. That's where I worked. /ubbthreads/images/graemlins/jpshakehead.gif
More and more of the base builds are done in the US (sometimes in the same HP building) but by a Chinese company though they are trying to retain many current employees. I remember when Compaq was a company you could be proud to work for. Not so much now with HP.
As far as actual components used, most companies use other vendors products. IBM, HP, Compaq, Dell, Gateway all have used or do use NEC, Sony, LiteOn, Seagate, Maxtor, Western Digital, ATI etc components. That's just the way the industry runs and shouldn't be held against them in particular.