Hehe, abit confused here.
Tablet PC Windows is Windows for one of them Touchscreen PCs... Acer made one of those. Not for a tablet.
Hymm, looks like you can use it. But still you can't use it fully, as you don't have a touchscreen. http://www.microsoft.com/windowsxp/tabletpc/
WinXP and Win2K also have an on-screen keyboard, is the one in WinXP Tablet a special one?
And what's Windows Journal?