The best and safest place to get Dell drivers is their own website. On the case of your Vostro is the Service Tag reference. Go to http://www.dell.com and find your country's local website and once you're there, click on Support and Drivers. Iinput that reference into the box and you'll be taken to the drivers for teh specific equipment that was put in your machine.
The downloads you will get are executable files so you need only to click on them and let them do the rest.