A940 drivers & utilities disk & download - errors

I see this problem discussed in other threads, but cannot seem to see a solution.  I have had my A940 installed for about two years on my Dell 8300 running Windows XP (using USB). 

 

The A940 has always printed fine, but today I wanted to scan for the first time.  The how-to leads me through start - dell printers - DellAIO A940, but there is no All-in-one centre option available.    Loading the supplied (sealed) drivers & utilities disk results in an error message " 16 bit window subsystem.  c:\windows\system32\autoexec.nt.  The system file is not suitable for running ms-dos and Microsoft Windows applications.  Choose 'close' to terminate the application."  Closing or ignoring does nothing. 

 

I downloaded the driver file "r56532.exe" from the Dell site, but same problem.  I also downloaded the Firmware file "R74855.exe". but it couldnt find some other file.   I'm no expert at all and am way over my head.   I ran a troubleshoot which recommended uninstalling existing drivers and reinstalling from the disk, but since the disk only leads to that error message,  I can see a problem occurring with that advice.  

 

I don't want to screw up the printing function, but would like to get the rest of the 4-in-1 working.  Any hints??