WINDOWS VISTA ULTIMATE - CAIN 4.9.14
Well, I had the same problem, it was a restriction issue and found a solution.
Turning off UAC was not enough, I had to activate the "disabled by default" Administrator account then installed and run Cain from that account without any problems.
How to activate the Administrator account:
1- Press the windows orb logo-> type in the search box "command" you'll find that "Command Prompt" shortcut had been isolated.
2- Right click the shortcut-> run as administrator.
3- The black command window will appear, type the following command:
NET USER ADMINISTRATOR /ACTIVE:YES
4- If you got " command completed successfully " then proceed to the next step, if you got " Access denied " then you didn't run the command prompt as admin.
5- log off -> log in using the Administrator account, install and run everything from there.
6- also install the openssl win32 just to be sure " don't know if Cain is using anything from it or not ".