I can understand if someone can't afford a new PC. But the ones still using 98, will not buy Win7, because if they can't install XP, forget Win7. For those who intend to buy Win7, most likely will have a 64bit processor. I'm not saying get rid of x86 7, I'm saying make x64 the standard.
You're making one *very* big mistake. If these folks are running legacy to ancient hardware and currently running Windows 98, then the ***last*** thing they are going to do is buy a ***NEW*** PC - they are going to buy a not so old (but still well out of the reaches of Vista and Win7) machine, like the Celeron 366 Laptop or Pentium 4 1 GB machine I have in storage.
I will not say that you must get x64 over x86 ... but if you are about to make a decision and your PC is compatible, then the answer is a no-brainer really.
I disagree- if your machine *can* run a 64bit OS, but you only have 1-2 GB of RAM, and the motherboard only had 2 slots so RAM expansion is not a probability without complete replacement, then I say *don't* get 64bit - you don't get a performance increase enough to warrant the increased use of RAM on the machine, and with only 1-2 GB onboard you're sacrificing a significant chunk of RAM for absolutely nothing.
@everyone - what it comes down to is knowing the requirements, limitations, and benefits / disadvantages of running a 32bit OS versus a 64bit OS. Just because you *can* run it does not mean that you should. A prime example is an analogous situation with my old (now wrecked) 1999 Infiniti Q45t - it was slated to run Premium unleaded fuel (93+ Octane) only. Now, there was one local gas station that actually offered 94 Octane - however, there was no real tangible benefit, and a definite tangible disadvantage - it cost ~ $.20 more per gallon, and this was when gas was knocking on $4.00 per gallon....on a 22 gallon tank, that was a big chunk of change, and the added $.20 only made it worse.
My car could easily run the 94 Octane, and there might have been slight performance improvement - but for the added costs of $4.00 per week, or ~ $230 year it simply was not worth it to me.
The same holds true here - if you have 4+ GB of RAM, you should not be thinking twice about x64.
If you have 3 GB of RAM you should consider it.
If you have 1-2 GB of RAM you need to really analyze the benefits versus the intangible *and* tangible disadvantages of running a 64bit OS.