I just had the same problem w/ a Lexmark X1185. MicroSoft web site gave me this that worked:

To work around this problem, use one of the following methods. Method 1: Copy the printer driver files to the System32 folder To copy the printer driver files to the System32 folder, follow these steps:

   In Windows Explorer, locate the following folder:
   drive:\Windows\System32\Spool\Drivers\W32x86\3
   Press and hold CTRL, and then click each printer file.

   Note Each printer driver file has a file name that resembles the following:
       lx**prpb.dll
       lx**prpr.dll
       dl**prpb.dll
       dl**prpr.dll
   Note ** is a two-letter designation that is associated with the printer.
   With the printer driver files selected, right-click the files, and then click Copy.
   In Windows Explorer, locate the following folder:
   drive:\Windows\System32
   Right-click the System32 folder, and then click Paste.

I don't see any printer driver files that look exactly like what you are showing me. Similar but not exact. And there are a lot of files - I do not know what to select and paste. I am not great at this stuff. I found w32x86 then 3 but can't figure it out from there. Help.

Thanks, this worked for my Lexmark X5150, for both Firefox and Thunderbird!