Go to Site Action and select Edit in SharePoint Designer.
In the Master Pages Gallery, you will find three files:
- v4.master
- minimal.master
- default.master
Don’t let the name default fool you, the one that is used for page layout in SharePoint 2010 is actually v4.master NOT default.master. So we want to copy v4.master before we make our customization and modify the copy instead (v4_custom.master).
Once done, just set it as a default page as indicated by the screenshot below (just do one or the other, not both).
