There is only one file type that uses the .VCO extension:
Virtual CD Collection File
Disc image file created by Virtual CD, a program used for virtualizing physical discs as files on the hard drive; created by the software's Collection Wizard and contains a grouping of virtual CDs; allows up to 255 virtual CDs to be inserted together as a single disc.
|HH Software Virtual CD||Commercial|
Updated: July 7, 2012