You've most probably downloaded the incorrect driver.
Originally posted by bracer028
...When i downloaded the new dell driver after installing vista, the "intel wireless" device said it is "not the correct operating system" or something like that...
Where did you download the driver from?
There isn't a Vista driver for your wireless device on the dell website's download page for your laptop, but there are vista drivers at the Intel website for your wireless device:
Is this where you downloaded the driver from, and if so, for which wireless device model, and for what OS?