Windows 7 Pro and above 64bit has access to a separate download called XP Mode which is a virtualized version of windows XP Pro 32bit that runs inside of windows 7.
Using XP Mode and a 3rd Party called VMWare they have a conversion software and a software called vmware player that takes the place of Virtual PC that comes with XP Mode. This works really well not just for the Lexmark x83 printer but for all hardware and software that only works with windows xp.
If you do NOT want to go through all that or your computer is not powerful enough to handle vmware then you are pretty much out of luck. The Lexmark x8350 is NOT the x83, I personally am not going to try the x8350 driver especially the 64 bit for vista.
The x83 NEVER had 64 bit drivers, production stopped on this model and support is non-existent.
I personally chose to use Windows XP Mode and it works well with vmware player which gives full access to the host hardware including USB ports, hard drives, individual folders, DVD player, external hardware like microphones, hard drives etc etc...
It's free and works great as long as it is for non-commercial purposes.
Might be too much hassle to go through to get just a printer to work but once setup you have a full version of windows xp pro so if you have software that didn't work with 7 or even windows 8 then this is a great solution. Though XP Mode is only available to Windows 7 Pro or Ultimate 64 bit. Once converted to vmware player then technically it is portable BUT the license may prohibit such activity. From a purely technical aspect it would work but moving it off of the hardware originally setup on you would lose the activation for windows.