if u dont have video memory, u wont have display...
point is...if u dont have a graphics card tht doesnt mean u dont have a video memory...if ur computer is generating display without a graphics card, tht means u have integrated gpu, which shares video memory from d system ram...
In Windows 7, to see the amount of graphics memory of your video card, right click on your desktop, select Screen resolution and then click Advanced settings. You will see the minimum and maximum amount of graphics memory in the "Adapter" tab page. Note that the minimum amount of shared memory may be shown as dedicated, but it is not actually dedicated, as integrated gpu does not always have dedicated memory, so look at the dedicated memory shown as the minimum...