To enable content approval for a list or a document library in your Windows SharePoint Services site, follow these steps:
Connect to your Windows SharePoint Services site, and then locate the list or the document library that you want to enable content approval for.
In the Actions area, click Modify settings and columns.
In the General Settings area, click Change general settings.
On the List Settings page, in the Content Approval area, click Yes or No to enable or disable this feature.