I recently got a new computer with Windows 7 64 Bit. I use a dell 3115CN and was having problems finding 64 bit drivers from the Dell website. There are no printer drivers on the Dell website, and the available printer driver failed miserably.
I found an thread on a forum that walked me through my 3115CN Driver Problem to a solution, which is actually quite easy: instead of trying a network install, try a local install. Click on the above link for a solution; I hope this helps someone.