Hi. This is my first post and i'm italian.. I've a pc with windows vista beta 2 (the release downlodable for free) installed on C: and a Windows XP installed on E: and my documents are on D:. Every operating system has 4 users. How can I make the documents folder private for 1 user on windows vista and 1 user for windows XP? Sorry for the english. Thanks for further answers.

If I understand your question When in Xp you want a folder protected to read only for one user and same folder read only for one user Are you the only admin. ? Understand that the operating system security is based on the hard drive and os that is managing it. so if you apply permission as admin in XP, Vista does not know what user you have give permission to, If you apply Permissions in Vista toa user, XP does not know that user account. So that only way to do this is to password protect files with no specific permission per operating systems. or each time you boot you have tochange permissions based on what os you are running, but as a xp Admin you can navigate any where in vista while running Xp if drive is NTFS, this would be hard to manage and you might forget. So you use file encryption as a simple way to protect you data.

use NTFS as your file system cmd--convert c: /fs:ntfs then you can secure the files by assigning a password when you are aske to make the folders private, respond yes

how can i assign a password to a folder?

assign a password to the user account you want his files to be private and u can right click the folder use the security tab of the file to assign proper permission just to the user u intend

and file encryption as he said is the best if you are not familiar with ntfs permissions

i can use the ntfs permission.. i want to know how give the full control to 2 user of 2 different operating systems. for example is any way to control the permissions and import a "key" of a user of another operating system and select the permissions of the other user?

.Are You are asking 2 operating system with 2 different sids to protect a folder on 2 different os. 1st why ? You could If you want to control a folder for 2 different user to be able to set permissions and share and protect set up a domain and the use the Domain user account to protect the Folder

I agree with Jay that using a Domain is the easiest way and in a business environment the preferred method. EFS would also work if you can use certificates that are trusted by both OSs.