Here's what I live by:

Rule #1: Dell sucks, except some LCDs, etc which are insanely discounted rebadged high end components (ie: 1095FP LCD). Buy Gateway desktops (quality support) and Lenovo laptops (quality hardware).

Rule #2: FDISK!!! The first time I power on the machine, it boots to a WinXP CD, formats the drive, and reinstalls a REAL copy of XP, not the bundled restore CD.

Rule #3: Tech support can tell you nothing that you can't find on the manufacturer's website (or elsewhere online). To get hardware replacement/repair, be patient and calm with their innane tests, doing only what they tell you, until they get to the part in the script that says "replace the part." The more calm you are, the quicker they get there.

Rule #4: PC vendors must get compensated BIG TIME for bundling all that crap on every computer. I asked Gateway if they could not install XP and, thus not charge me for it, since I'll FDISK instantly anyway. Nope, "it's part of their licensing agreement." So is Google Desktop, Mcafee, RealPlayer, etc. Build the price of retail XP and Office into the price of the computer.

Preinstall annoyance story:
When I first turned on the hot new Lenovo X41 tablets I got for work, they ran NTFS-to-FAT conversion!! Then, gave me all WinXP mini setup (no complaint there) and all the disclaimers. When the CPU stop churning after probably 40 minutes, there were about 14 systray icons, some systray search app, and enough windows open that not one pixel of the taskbar was blank. And every boot thereafter takes at least 5 minutes.

FDISKed with XPTablet, Office 2003, OneNote, etc, these things are lightning fast and my staff think they're a joy to use. Time spent doing clean software install (then making a Ghost backup image CD for when the computer owner gets spywared to death so you can quickly restore) are worth it 1000 fold.