X-COM: Apocalypse has been one of the trickiest games in the X-COM series to get running under Virtual PC. The run down of the issues that I encountered while setting this up were:
1) X-COM: Apocalypse seems to have a problem installing off of a .ISO file instead of a physical CD ROM. Installing off of a .ISO file results in the installer crashing when it tries to determine speed of the CD-ROM. In order to install I had to use a physical CD – then things went fine.
2) X-COM: Apocalypse also has the ‘Internal Virtual Machine Error (3)’ problem (discussed in this post: http://weblogs.asp.net/virtual_pc_guy/archive/2004/10/21/245528.aspx). So in order to work under Virtual PC – X-COM: Apocalypse needs to be run under a Windows 95 / Windows 98 virtual machine.
3) X-COM: Apocalypse uses a VESA display mode that is not compatible with the video driver that is installed with the Virtual Machine Additions – so in order to play this game I had to use a Windows 95 virtual machine without the additions installed.
Once I had done all this – it ran just fine: