There no such model listed on the Asus website. That usually means one of a few different things:
1: You submitted an incorrect model number.
2: It's an OEM motherboard in which case you have to visit the website of the company who made your computer.
3: It's too new to be on their website or they have no plans to put it on their website.
They do have a couple other models listed that are close to your posted number:
Drivers for Asus p5vdc-x
Drivers for Asus p5vdc-mx
And when asking for a Graphics/Video Adapter driver it's a good idea to describe that Graphics/Video Adapter like in "VIA S3G Video chipset that's integrated on the motherboard".
When you choose "Other" in the interface box, we have no way to know if your video is a chipset integrated on the motherboard or if it's an add-on PCI/AGP card.