I used to be like your friend. I would say "I'll build you one cheaper and better than one you can buy." And that part was true. I'd set the system up the way I wanted, and it would be perfect and clean and fast for games.
The problem is that the people I built it for didn't use it the way I would, and so there was frustration on both ends when they wanted to do something else. And there was
special frustration when they installed something I wasn't familiar with and then wanted my help to fix it if it did something odd. Things got worse when distance was involved.
In short, your friend means well, and probably does not understand why this is a bad idea, but it is a very bad idea. When "some guy" builds your computer, "some guy" is your ONLY source of support.
As for buying a prepackaged PC, I am overcoming my reflexive dislike of HP that I developed some 10 years ago. As a matter of fact, my current "gaming" PC is a $650 HP system that I added parts to. It works quite well, and since HP uses standard parts it was no problem to upgrade. I used to like Dell a lot, but strangely they seem to have lost quality *and* value at once, and so I'm not so sure now.
From your description, you don't need a gaming system, but since you seem to be a long term user, there are some component choices I would make to "future-proof" it in case something breaks 5 years from now:
(Also note: you don't need to know what these things do, just what they are called.)
- 64-bit processor (this means an AMD, not Intel)
- Serial ATA (SATA) hard disk (not IDE)
- A PCI Express slot (Not AGP)
- 2 Open DIMM slots
Because you currently have an older computer and probably don't want to set up a network to transfer files, you probably still want a floppy drive for your new computer. This isn't included on most new ones by default.
How much do you want to spend? A basic, cheapest-of-everything computer can be had for around $600, but I would recommend something in the $1000-$1200 range.
Also, do you need a new monitor? I would recommend a 17" LCD if you do not have a LCD, or maybe a 19" if you want to get really fancy.
Do you have a digital camera, or anticipate wanting to use one in conjunction with your computer? A digital video camera?
Do you need a modem still, or do you have high-speed access pretty much everywhere you might use this computer?
What word processing software do you use? Would you want to get a new version of it, or maybe use something else? Is there any software that you need to use for file compatibility with work or something?
I can recommend a general configuration once I know what you use and what you want to spend.
(Edited lots 'cause I keep thinking of new questions)