How can I reposition scenes in a WMV file ?

[narf]

Hi there,

I downloaded a wmv file from the Internet but this one is
different from the others I'm used to. I think that in order
to shrink the video's original size, someone took away the
feature that lets us use the player's slider to reposition
the scenes.
That forces me to watch for the whole video even when I
just wanted to see some of the final scenes.

What can be done ? Does anybody recommend another
software that takes this video as input and generates
another one "reposition-enabled" ?

Thanks a lot,
Narf