It won't work on my "modern system" as I have Vista64. As far as establishing compatibility for the individual customer goes, "modern systems" is non-information.

Discounting XP for the obvious reason, do people really still use 32bit extensively? Pretty much everyone I know has switched to 64

Many people are still afraid of 64-bit operation systems. They think that most games and other software are going to stop working if they switch to 64-bit. How they came to this conclusion is beyond my understanding. For me 64-bit Vista has always been far better than the 32-bit version I have on my laptop. Surprisingly there have been far less compatibility problems (EDIT: with older games) with the 64-bit version.

I'm buying a new PC, and will be getting Visa64 (with a view to getting win7), and I can't think why you would choose vista32, if you wanted a 32bit OS, surely you'd just get XP...

XP is still virtually exclusive in the corporate / business world, although there might not be too many CEOs around that like having their employees play GOGs.
I'm still on XP32 too, that's due to change with Win7 release though.

businesses aren't really in the scope of the discussion of games (well they SHOULDN'T be anyway) but yes they have always been slow on the uptake, suppose the don't fix whats not broken has always been a business rule.
XP doesn't really count since it's 8 years old and predates the general availability of 64bit CPUs. Also from most reports the 64bit version of XP is so shit it's almost pointless to use it

I switched to 64-bit before Vista became available :-P
Sure, there were a few troubles getting drivers for XP x64 as it was never meant to be a commonly used system but basically just created for a few large customers needing to make use of the extra possibilities (yeah, not like I paid for it or got it through any other legal means), only when Vista was released - and with it the requirement to support 64-bit systems if you wanted various "works with windows" brandings - did many manufacturers bother supporting XP x64.
But yes, at least here, some "flavour" of 32-bit Vista is what comes with most computers, very few has 64-bit Vista (almost only "gaming" setups and powerhouses with more than 4GB of RAM) and some business-oriented machines has 32-bit Vista with a downgrade option to XP (together with the upgrade to 7 that comes with most machines nowadays), only a very small number of netbooks still has XP only.

The question was does it work in modern systems, not 64 bit modern systems. The non-windows (emulated) games do work in 64 bit os's though. As a matter of fact Gametap offers a discounted sub that only includes those games for 64 bit machines.
Even though 64 bit can now be considered the main flavor of Vista, there are still plenty of entry-level pcs/laptops that have 32 bit Vista on them. I just bought a HP laptop for my son for school and it had 32 bit Vista Basic on it (blech!)

I do, dont see the need to run vista at 32bit, and I dont see enough reasons to switch to windows 7.

You are aware of how wrong that argument is, right? By your reasoning, it would be perfectly reasonable to advertise a game that only worked on 1 particular recent distribution of Linux as being "compatible with modern systems".

Erm, 32 bit Vista is just as modern as 64 bit Vista. They were both released at the same time and have the same service packs released. It's like a brand new car that comes with a high end V8 that needs premium fuel while the six cylinder version uses regular. If a gas station doesn't carry premium fuel, the high end car owner is screwed. 64 bit is the high performance version of Vista and Gametap is like the one fueling station in the city that doesn't carry premium fuel.

And OSX 10.6 is even more modern. But games in general don't work in Linux or OSX unless you do something special. So now your starting to get rather silly with your argument.

Allright, let's rewind, then. According to the latest set of Steam hardware statistics (which was the best measure of current gaming PCs I could find), 18.5% of Steam users have a 64bit OS. This means that nearly 1 in 5 gamers apparently doesn't have a "modern system", even though it is either as or more modern than the ones covered by that statement. As an argument for using a gaming service, it needs at the very least a "most" inserted, as in "most modern systems", preferably with an explanation of exactly which systems are compatible and which are not. This would of course make the "most modern systems" statement completely redundant, but there you go. Anything less would be highly misleading.

Of the however many millions of Steam users there are, 18% is actually a large number, and honestly I bet encompasses most of the "hardcore pc gamer" base.