Make sure your computer has the latest Windows Updates, especially .net framework, needed to run many applications and the latest Java.
Download and run the patch (a MUST on Vista machines) until it prompts you to restart your computer.
Restart your computer
Download the Vista 32-bit Drivers
Install the Vista 32-bit drivers. You'll be prompted when to connect your printer(powered on)
As for scanning, if you have the disk that came with the printer, then insert the Printer disk and stop it from running. Go to My Computer and double click on it. Look for the drive with the Dell disk in it. Right click on it, left click explore. Look for the OCR Folder. In the OCR Folder, there is an Abbyy Folder. right click on setup.exe, that's in the Abbyy Folder and left click run as administrator. This will install the OCR program.
Scanning using USB connection, open the Dell All-In-One Center, click on scanning and copying and scan from there.
Scanning wirelessly, use the scan buttons on the printer.
Let me know what happens.