Okay, here's the story; Dell isn't necessarily a bad computer. In fact, they're well made, and they run just fine, but there's a couple of problems with them that a consumer may want to be aware of, especially if purchasing multiple units for business:
Well, that doesn't sound so bad; what's wrong with that? Answer: (Continuing with our power supply example) say you need a new part, and your warranty's expired. You can't go to the local shop and pick up a $30 power supply unit. You must go to Dell, go through a huge hassle on the phone with customer "service" to find the correct part number that corresponds with your board, and after dismantling your machine to give them three or four hard-to locate serial numbers, they will inform you that the part costs (as of 2003) $278.95.
People, we're talking about a power supply. how many times has a tech ever told you "Well, this would have been a 2-minute fix if I had realized you had a different brand of power supply."? It's a box which suppplies 5 and 12 volt power to the unit as a whole, not rocket science. The truth is that Dell is profiting pure and simple because once you buy one of their machines, you're trapped into buying parts at 1000% (10x) of what you'd pay at a local shop or to order the part online from a reputable computer parts site. There is NOTHING that an off-brand power supply can do to a computer that is hard to diagnose. A power supply problem is a power supply problem and easily spotted by a competent computer technician.
If Dell comes out with a blue, transparent, spherical floating power supply that powers your computer whenever you pour decaf coffee into it, THEN I'll buy into the "proprietary is better" line. Until then, we're all getting fleeced on repairs.