Enable document library event handlers

1. Click Start, point to All Programs, point to Administrative Tools, and then click SharePoint Central Administration.
2. In the Virtual Server Configuration section, click Configure virtual server settings.
3. On the Virtual Server List page, click the name of the virtual server you want to configure.
4. On the Virtual Server Settings page, in the Virtual Server Management section, click Virtual server general settings.
5. On the Virtual Server General Settings page, in the Event Handlers section, next to Event handlers are, select On.
6. Click OK.

After you enable the feature, you can write code to handle the events, and then specify the code to use for a particular document library in the document library settings.

1. On the appropriate Web site, navigate to the document library you want to monitor.
2. In the Actions pane, click Modify columns and settings.
3. In the General Settings section, click Change advanced settings.
4. In the Event Handler section, in the Assembly name box, type the assembly name for the managed code you are using to handle events for this document library.
5. In the Class name box, type the class name for the event handler.
6. In the Properties box, list any appropriate properties for the event handler.
7. Click OK.

Note  Microsoft Windows SharePoint Services preserves event settings when you save a document library as a list template.