windows 7 - Renaming files according to the folder they're in

I have hundreds of folders named after movies. In each folder there's a .mkv file (or .avi, .mp4), named differently. In each folder there's a folder.jpg.

I'd like to rename each video file so that it carries the name of its parent folder. folder.jpg must stay unchanged though.

For example, the folder structure is like this:

 - Movies/Stirb Langsam 1/stlg1.mkv
 - Movies/Stirb Langsam 2/stlg2.mkv
 - Movies/Star Wars 1/hhgdtebds.mkv
 - Movies/Star Wars 2/stwa2.mkv

And should be:

 - Movies/Stirb Langsam 1/Stirb Langsam 1.mkv
 - Movies/Stirb Langsam 2/Stirb Langsam 2.mkv
 - Movies/Star Wars 1/Star Wars 1.mkv
 - Movies/Star Wars 2/Star Wars 2.mkv

At the moment I use Windows 7 for that. Would be nice if one of the scripting gurus could help me.