In short XP x86 is Windows 5.1 XP64 and Server 2003 (either 32 or 64 bit) are Windows 5.2 It's not different from Win 8 which is Windows 6.2 and Win 8.1 which is Windows 6.3 They are closely related but at the same time they are different OS releases. You can easily get XP52 using Server 2003 x86 and switching it to client using tweakNT or ntswitch In the same way you can get Server 5.1 (ake "Server .net" as it was branded at the time) switching XP 5.1 to server mode.
So just to confirm that I’m understanding correctly: there are indeed differences between XP and 2003 (R2) and 2003 (R and 2003 R2 are the samebut within those product families there’s no difference between the editions or service packs (e.g. server 2003 Enterprise Edition RTM’s version of the needed files is the same as RTN Standard Edition which are the same at the R2 variants of the same name whereas XP RTM Pro and home are also the same) thanks
Sorry, but that's exactly the opposite of what I wrote XP (32) and server 2003 (32) are two different windows releases: Win 5.1 v.s. Win 5.2 XP64 and server 2003 (64) are two flavors of the same OS Win 5.2
oops… It was a typographical error. I’ve since made a correction in my initial post to indicate that XP and server 2003 are indeed different but within the two product families they are the same i.e. XP home and XP pro are same yet XP pro and server 2003 (R2) are different
In some areas they are profoundly different, the Windows NT 5.1 and 5.2 that is, e.g.: a whole group of file system filter drivers is unavailable on WinXP, that is FS Filter Virtualization. Diskeeper's wonderful Intelliwrite uses this but for XP it has to use higher altitude "Activity monitor" filter altitude "temporary fix" otherwise it's literally unstoppable as a service. Works though, especially with KB970158 installed. Just as an example from my poking around... You can find more info on easefilter site MiniFilterAltitudes.