This is a very sensitive topic, especially in this tough economic times. You may need to disable a bunch of users and you want them offline now!
Windows unlike Novell, does not really kick a disabled user out. Some one sugggested doing this.
1) Disable Cache Logon + assign GPO that run a login script “shutdown -l” to these group of disabled users.
2) “shutdown -l -m \\computername” then delete his computer account from domain.
Sounds a bit drastic, but it might work. Personally I prefer to reset the computer account. From here . Might need logon to get pass the paywall.