Restore Method
The Restore method of the SPFileVersionCollection class restores the file version object at the specified index in the collection.
Parameters
iIndex A 32-bit integer that specifies the index of the version to restore.
Remarks
If versioning is enabled for the document library and the file is not checked out, the current file becomes the most recent version when a version is restored.
Using the Restore method is the same as using a combination of the OpenBinary method of the SPFileVersion class and the SaveBinary method of the SPFile class, as in myVersion.File.SaveBinary(myVersions[5].OpenBinary). However, the Restore method is more efficient.
Requirements
Platforms: Microsoft Windows Server 2003
Security: Code Access Security