>Well I lost my default shares C$, d$ etc on NT server. I wasn't here for about one week and I don't know how it could be happened (other administrators claim they did nothing). Any clue to get them back ? MTIA
Cetin, while you may be able to recreate them, my experience is that this is likely to be a file system error, especially on an NTFS volume. The first step in the repair process should be to run CHKDSK /F against each drive where the share has been lost while logged in as a user who is a member of the Administrators group for the local machine and then restart the system, allowing CHKDSK to examine all the security descriptors (and the rest of the file system as well.)
It is important to be a member of the local Administrators, and not assume that you're OK if you think you're a member of Domain Admins, since if the station is having problems contacting a domain controller, or your domain rights have been altered, you might not have the privileges you expect; in the first case, because the domain controller cannot validate you even though you might have an account on the local system, and in the second, because Domain Admins may not have been granted all necessary permissions.
hth,
Ed