Batch rename part of a file in windows

In the command window:

REN foo_bar*.jpg "foo bar*.jpg"

From the how-can-i-mass-rename-files-in-dos question asked about an hour after mine I have actually found a really good free tool that does exactly what I want: bulkrenameutility it is a free rename utility. It is kind of confusing at first, but I like the preview mode, and it can do regular expressions, seems very powerful!

There's a freeware file renamer utility that I use that's pretty easy to get into. All you need to do is to choose the files that you need renamed, make sure the correct options are selected, and then to apply the changes.

It also has a handy "Undo" feature that you can use if the changes you just applied wasn't what you were looking for.