If you want to animate, say, an avator or a sig or something, you'll need a program that creates GIFs. A quick Google search pulled this up –
http://www.gif-animator.com/
If that doesn't work, I think Windows comes with Windows Moviemaker doesn't it? Import your images in there and use some effects to compile them together.
If you're on a Mac, then Macs all come with iMovie. You can create a movie using the clips and animate them with Ken Burns effects and add transitions and such. That's exportable as a QuickTime movie which any computer can read and it can also be burned onto a DVD using iDVD.