Notes about the HVA file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The HVA file type is primarily associated with 'Tiberian Sun' by TiberiumSun.com. Also used by Red Alert 2. Voxel .HVA files will have correspondingly named .VXL files that specify the animation to be used in the game; the HVA files say how the animation is used.