Click Start > Run
Type "gpedit.msc" and hit Enter (or click 'Ok')
When the Group Policy editor comes up, open the tree under:
Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options
Scroll down until you find "Disable CTRL+ALT+DEL requirement to logon"
Double click on it and select "Enabled". Click "Ok".
Restart your system....
Let me know if you run into any problems.
*Note, this will only affect the local system, and does not affect any other systems on your network. To affect ALL Win2k workstations, you need to edit the Group Policy for your domain or OU.