Micah has a question:
How do I convert an ASF file to an mp4?
Now, video conversion takes time and sometimes results are not what you expect. Online video conversion might be even more troublesome, specially if your file is rather large. Also, the size of the file they converrt for free might be limited.
Did you try to view your video file using VLC? It's free and plays readily almost all video formats, including ASF.
Also, you can download K-Lite codec pack, it's free, for Windows Media Player. Latest version is available at
You can select the pack of your preference: Basic, Standard, Full, Mega and Update, guess Full pack is more the enough for your needs.
Install and then download Update
De careful not to change your default players for some audio / video formats, if you have any i.e.: mp3 player. You might not be quite happy with the result.