Some virus checkers are quite aggressive with quarantining unknown files. There have been a few instances where virus checkers quarantine the Surfer.exe file, or the DLLs that Surfer uses, even in the middle of running the application. If the Surfer application disappears from your computer when you are running it, or between instances of running it, please check that your virus checker did not quarantine the file. You can either unquarantine the file, or sometimes updating the virus definitions solve the issue.
Updated January 9, 2017