How to Export & Import Encryption Keys

Summary - I exported the encryption key & certificate to another computer but can't open files there.

Details - I'm running the XP-P with SP3 on two workgroup networked computers. I have successfully encrypted and decrypted files and folders on computer 1 using EFS (right click folder-properties-advanced-appropriate checkbox, etc.). Then I shared the folder for editing on computer 2.  The folder is now viewable on computer 2 but of course I get "access denied" when I try to open a file.

So I exported the personal key from computer 1 via the Internet Explorer (IE-tools-Internet options-content tab-certificates-personal-select-export-next-export private key-next-strong protection-next-set password-next-browse for location to save the PFX file, etc.). Then I installed the key (the PFX file on computer 2 by double clicking it there selecting "make it transportable" and verify that it is now listed in the "personal" keys using the Internet Explorer).

Then I restarted computer 2 and expected be able to open the encrypted files on stored computer 1, but I still get "access denied". What am I doing wrong? I read lots of posts here and much from Microsoft. Help appreciated?