I use Hyper-V. Is it possible to upload Hyper-V disk images and use them on the ElasticHosts system?

Yes, although they must be converted first: our system requires either DVD or CD images in .iso format, or raw disk images. Microsoft’s VHD file format can be converted to raw format using qemu-tools:

qemu-img convert -f vpc inputfilename.vhd -O raw outputfilename.raw  

If they are installed, it’s important to remove Microsoft’s Virtual Machine Additions before converting, as these non-standard drivers can cause problems on our system.