The cheap barebones bundle I built my Mom from a package I bought from TigerDirect will run AH II better than most Dell or Compaq computers I've seen.
About 90% of what Dell and Compaq use is PROPRIETARY. Sure, maybe Seagate or Maxtor makes that HD, but they make it to Dell or Compaq specs. Yeah, Sony might make their CD/DVD/floppy, but not to Sony spec.
The memory is cheaper grade, so is the video card, and damned near everything else. Not only that, but aftermarket parts WON'T WORK half the time, meaning you pay DOUBLE for out of warranty replacements, and you CAN'T UPGRADE, at least enough to make it wortwhile. You can't even upgrade the software half the time. In 6 months, it's THREE YEARS behind the times. Not to mention their modems suck 90% of the time, and a good modem is critical to AH.
Pick up a couple of books on building PC's, there are several on the market. Keep your old clunker up and running until you get the new one rock solid. The old one will take you to any number of BBS's where you can get free help from people who help because they WANT TO. Buy from a reputable company, I use NewEgg, ExcaliberPC, Monarch, and sometimes TigerDirect. Do some research, and know what to buy.