OS Version: 10.6.3
After trying to connect to the machine that is running Windows 7 using Samba and failed. I got a error message when trying to open Finder. “The application Finder can’t be opened. -10810” If you have the same problem you can try each or all the solutions listed blow.
(1). Go to Activity Monitor 
and choose WindowServer and then click “Quit Process”. This will log you out off the current window session. Be sure to save unsaved work before doing this.
(2). Type: /System/Library/CoreServices/Finder.app/Contents/MacOS/Finder & in terminal ( utvv.blogspot.com/2010/01/how-to-fix-application-finder-cant-be.html )
Image Credit: Georg Portenkirchner