Differing versions of XP Pro?

Has microsoft released a significantly altered version of XP Pro recently?

I have two XP machines, one is 7 months old, the other is new. Both are running XP Pro, however, one XP seems significantly different to the other in certain places.

For example, right clicking on a folder and selecting 'Sharing' renders two completely different dialog screens, with different settings and options on each.

Any ideas?

Well there is a professional edition called corporate edition.. Well this is sold to big computer companies to load the OS on the systems they produce.... This does not require the activation and stuff but is basically an pro edition.. And everything including the name is called as professional edition but since it is sold in buls liscence it is called XP pro corporate edition...

Theres 4 xp versions:

Home
Professional
Corporate
Professional Corporate.

I use the last one, the difference is that it has no restrictions on anything, at all, if u wanna get it u gotta be a super-huge corporation of know someone in microsoft, and it'll run you about $10,000.00 US, yes ten thousand..

I got it from my grandfather, who (lucky for me i guess) is a programmer for microsft.

edit: // Theres also no licenses.