@'What does it offer'
Well, Vista and 7 were designed to start making the system more stable, secure and consistent (i.e. so that you don't get noticeably different features on different hardware), but sadly all the whingers don't understand there are tradeoffs with this..
Only 64 bit versions of Vista and Windows 7 support more than 3GB RAM. It seems PAE is enabled on Vista, but doesn't support access to higher than 4GB RAM as this has an impact on driver support. PAE is a nasty hack on 32bit Windows Server OS and should be avoided wherever possible anyway..
To say that XP/Vista/Windows 7 isn't an improvement over 98 is laughable. Just because the improvements can't be seen running a web browser in an English speaking country does not mean they're not there.
However, the main reasons are
1) it's no longer supported
2) No more security fixes
3) Programs generally don't support 98 any more, because it's a sack of limited, unstable buggy shit that's a horror to program for.
4) Little new driver support, either.
The price of computing with a PC is that you have to update your computer and operating system about every eight years or so. This is *not unreasonable* especially given the dirt cheap cost of hardware.
98, and even XP 32bit, are not architected to cope with all the new media people are/will want to use. Updating operating systems to handle new security threats, better networking and utilising new hardware is not free.
Do you really think that all the OS vendors are upgrading their architecture for fun? If 64 bit was truly a dead donkey and everyone could cope with a single processor, english interface with piddly disks and naff all memory then someone would not be bothering and gaining competitive advantage.
As it is, companies have to do forward planning, which is why they have to include features that don't appear to be directly applicable to some people, unless they bother to examine the technical background.
Which is not to deny, of course, that sometimes they fix the problems in the wrong way and have to try again.