If you go to add a webpart, choosing the ‘Content Rollup’ category and you can’t find the Content Query Web Part, it’s actually a very simple fix.
As it most probably turns out, you don’t have Publishing activated.
Just to go Site Actions/Site Collection Administration and then click the ‘Site collection features’ link. Down toward the bottm, you will find ‘SharePoint Server Publishing Infrastructure’. Just activate that feature and it will appear in that site collection when you need it.
All Things DotNet Discussed – Winforms/ASP.Net/SharePoint/WPF