changing passwords on a mass scale

Use active directory to set a group policy.

Use group policies to force change password across the domain.

Go to Security setting, Account policies, password policy and change the default setting.

What about a WMI script that set all the passwords to expire, thus all users would be forced to change them when they login next. If you decide to go down that route I will post a script....

This assumes that you are in a position to initiate; There are several methods to originate new passwords as well as to issue them so I won't address this; simply initiate a new batch of passwords and issue them the next time they log on to the system, dump them out of the systems and require them log on again with their new password. I wish I could say it would all go smoothly, it won't and it is worth it as usually you find out all kinds of wonderful things about the Company you work for, also this is one of those periodic things companies do.

RIVER FREIGHT

Rather than the script to set all passwords to expire, write it to force "User must change password at next logon." Or if your OU's are small enough, you can even do it the point and click way in AD users and computers.

Good luck,