I wanted to convert an Asf file to an Avi file using Virtualdub1.3c. I installed mpg4dxk and when I tried to open the Asf file in virtualdub1.3c an error pops up saying ASF: Data chunk not found. Any ideas?

The Asf file according to its properties>advanced tab says both it's video and audio codecs are WMV V8 so I can't use asftools according to doom9's guide.

The Asf is just under <1gb. I tried converting that in Tmpgenc to mpeg1 and it ended up being over >2.4gb so I tried compressing it to avi using divx 5.1.1 codec in virtualdub but that ended up being over >3.8gb. This conversion stuff is tricky.