I need a copy of cardfile.exe from windows 3.1 does anyone know where I can download it??

Microsoft application Cardfile came with Windows for Workgroups (v3.11)
Cardfile was also included with Windows 95, Windows 98 and Windows 98SE.
I will only go back as far as Windows 98SE for this answer.

Reference: An application called WinAce (similar to WinZip but much more powerful) can be used to open/view Windows CAB files and allow you to select specific files to extract.  http://www.winace.com/ for a free / trial copy of WinAce.

An updated / complete version of Cardfile.exe is located / can be found in the Windows 98 Second Edition Cab File win98_44.cab.

Also, contained in the win98_44.cab file is the cardfile.hlp which you will also want to extract.

Once the files are extracted you will copy the files to the following locations:
For Windows 2000 Pro:
 Copy the Cardfile.exe file to your //WinNT/System32 folder
 Copy the Cardfile.hlp file to your //WinNT/Help folder

For Windows XP Home and Pro:
  Copy the Cardfile.exe file to your //Windows/System32 folder
  Copy the Cardfile.hlp file to your //Windows/Help folder

You now have to create file association for files created with cardfile.exe.
By default the file extension of saved Cardfile.exe files are called xxxxxx.CRD.

To create file association under Window 2000 / Windows XP do the following:
 Open Windows Explorer and select "Tools"
 Select "File Types"
 Select "New"
 Enter the file extension type (in this case the entry will be:  CRD   )
 Select the application to open the file with; You will browse for the application name "Cardfile.exe" which you    
 located (Under //Windows/System folder  or //WinNT/System32 folder
 
Once the file type association is created you can scroll down Registered file types and find CRD and select "Advanced"
In the first entry field you will specify a description of the  CRD file extensions. This description appears in folder windows when you display files in "Detail" using Windows Explorer.
In the second entry field labeled "Actions" you will select "New"
In the New Action box you will enter "Open" under "Action"
In the New Action box you will browse for "Cardfile.exe" (see above for location)
No not select DDE (Dynamic Data Exchange) as Cardfile.exe does not support this feature.
Choose "OK" and "OK" and "Apply" and "Close" on the applicable dialogue boxes.
You are done.

Now, you probably want to create a shortcut to your saved cardfile collection (xxxx.crd) you will need to create a shortcut to your xxxxxx.crd file in the same directory where it is located.

My preference is to copy the shortcut you just created to the C:/Program Files directory.
You can then copy the link to the start menu (also known as Pinning to the Start Menu).

Note: Don't be suprised when you see a file by the name of CARDFILE.GID created.
The WINHLP32 file will create the CARDFILE.GID when you access the help functions through the Cardfile.exe Pull Down Menu.

I still use the Microft Windows Cardfile to this day on my home network and Server networks with no problems.
My wife and gradeschool kids understand how it works and they use it with no problems.
It's only a 16-bit application but it's small and everyone seems to understand how to use it.

Cardfile supports imbedded graphics and a neat trick I use is to "Add" a blank card.
As the card file naming structure will place the blank card as the first card viewed you can add / imbed any family graphics (photos, word art etc.) as the startup image everyone will see when they open your shortcut link to the Awesome Microsoft forgotten program Cardfile.

Technical note: Windows 2000 and Windows XP perfers 32-bit programs yet completly supports a 16-bit application. You can identify 16-bit programs running (like Cardfile.exe) in taskmanager. Windows Taskmanager will have programs running called wowexe.exe and Ntvdm.exe which is the virtual DOS machine environment that was so popular in Windows 3.11. You will also be able to identify the 16-bit applications by viewing Task Manager tab "Processes" where you will see 16-bit applications indented from normal 32-bit applications under the Image Name column.