Download VDubMod from http://www.free-codecs.com/download/ VirtualDubMod.htm.
VirtualDubMod _1_5_10_1_All_inclusive.zip file is about twice as large as the VirtualDub download file. It’s bigger because it’s all of what’s in Virtual Dub and more.
Extract it from its zipped file and install as you did VirtualDub, placing the files and subfolders in any folder. An installation process isn’t included or needed. The following figure shows the files and subfolders you’ll have: