This depends on the reason of the "bad file" error.
Edit/create your autoexec.cfg and add the line "log on" to it.
Now restart your server, wait a few minutes and then shutdown the server.
You should have now some log files in the "logs" subfolder of "cstrike".
Open the last one (the newest) and start reading it, right after some lines about "MetaMod" you should see an error message which indicates why you have a bad file, e.g. file not found or some library dependencies.
Post this error here and wait for further advice
