Is graphic card is compulsory for VideoScribe? why VideoScribe is crashing when clicking on save with 1080HD WMV format, 25 Frame? 

It's not likely to be anything to do with your graphics card but more likely a general memory issue with the VideoScribe application. WMV and AVI renders use more memory than MOV and if it's a large scribe the memory limit is reached more quickly. VideoScribe can use around 1.2 GB of RAM regardless of the amount of RAM available on your computer. I would recommend either rendering as a MOV file or sending your scribe to sho.co our remote video rendering and hosting service. You can send a scribe to sho.co for rendering in VideoScribe by clicking the 'Share Video Online' button on the 'Create a video' screen. You will be able to download an HD MP4 version of your scribe from sho.co.