Yup

I found there are 4gb dimms available in ddr3 1066mhz from Kingston. However, there seem to be multiple options so IT-idiot me is kind of confused (no change there then )

http://www.ec.kingston.com/ecom/conf...z%2C%2C18%2C22

Examples:
Kingston KAC-MEMH/4G - http://www.ec.kingston.com/ecom/conf...C-MEMH/4G&id=8
Kingston KFJ-FPC413/4G - http://www.ec.kingston.com/ecom/conf...FPC413/4G&id=8
Kingston KTA-MB1066/4G - http://www.ec.kingston.com/ecom/conf...MB1066/4G&id=8

Yet another question: How, other than obviously contacting dell's CS, would I tell the maximum memory allowable on the stock motherboard? Is there an option from (vista64) control panel or system?