You need to register the directory with Oracle. fopen takes the name of a directory object, not the path. For example:
(you may need to login as SYS to execute these)
CREATE DIRECTORY MY_DIR AS 'C:\';
GRANT READ ON DIRECTORY MY_DIR TO SCOTT;
Then, you can refer to it in the call to fopen:
execute sal_status('MY_DIR','vin1.txt');