Here's how I got my Lexmark printer to work in Windows 7:
I have a X2470, but hopefully this will work for others as well.
1. Download the Vista
drivers for your printer. For me it was cjr2400EN.exe
2.
Do NOT click on the file to execute it! Instead, right click it and unzip to another folder (mine was named cjr2400EN).
3. In that folder, find Setup.exe. Right click on that file.
3. In Properties, select Compatibility.
4. Select Run this program in compatibility mode for: Windows Vista
5. At the bottom, check Run this program as an administrator.
6. Click Apply and ok.
7. Then, click on the setup file as you normally would to install. From that point on my install was normal and the printer seems to work fine.
Hope this helps!