The Windows version that came with my ASUS only contains the drivers for that particular hardware and won't work on a different computer.
That's where you're wrong though. All Windows SKUs, OEM or otherwise, should* come with support for popular hardware (read: drivers submitted by vendors for inclusion in the OS). Any system that works with a retail version of Windows will work with your OEM version of Windows, assuming the drivers and software Asus has bundled fail or exit gracefully when they can't find the hardware they need. (Windows drivers behave like services, and they should just exit cleanly if they don't find supported hardware.) Anyway, you can try it yourself and install your OEM copy of Windows on VMware or Virtual PC.
I was referring to the actual files on the computer. The Windows version that came with my ASUS only contains the drivers for that particular hardware and won't work on a different computer. Sure, I could probably piece together something that works using those files and drivers I download from the internet but how's that different than those people trying to hack together a version of AmigaOS4 for the MacMini using the AmigaOne OS4 distribution.
See above. *It's certainly possible for Asus to remove unnecessary drivers--it's done all the time in the corporate world to speed up the unattended build process (which we lovingly refer to as the unintended build process); however, for a company like Asus that builds hardware and bundles other vendors' drivers (rebranded or not), it doesn't make sense. It takes more effort to remove drivers from Windows, where the installation information for most drivers is integrated into a core set of INF files, than it does to add new ones, which are now just dumped into a directory scanned during setup.
I've only been supporting Windows for about 17 years now, so it's possible my memory of how things work is fuzzy or incomplete. ;-) Or things could have changed in the OEM world. These days, I do as little I can to get the job done, and that often means glossing over information that just isn't relevant to what I'm doing.
Now, all that said, if Asus really has produced an OS CD that only includes Asus drivers, then I have just lost a whole lot of respect for them. What a waste of time and no wonder my new X58 motherboard cost more than 300USD.
Prior to Windows 2000, you had to modify Microsoft's INF files if you wanted to truly integrate your drivers into the OS setup. You could use the OEM setup process, but that just wasn't as cool, and the drivers weren't integrated into NT's standard applets for adding and detecting display, network, sound, and storage adapters.
Anyway, back to OS4. If an OEM wants to bundle OS4 with their hardware and simplify the installation process for its users, awesome. More power to them. But if a user wants to buy an off the shelf copy of OS4 and run it on a supported platform (with vendor-supplied drivers, if necessary), they should not have to choose between five or six identical boxes that may or may not include boot and kernel support for their board.