File permissions question
Solution 1:
If you set everything to 777 then right off the bat, you know that something else is up.
That being said, standard permissions for your files and folders should be : - for folders : rwxr-xr-x (755) - for most files rwr--r-- (644)
In your case, since you've just migrated your site over to a new server, you'll want to verify your web server configurations and folder paths. Specifically, your web browser ought to be able to execute your php files. If suexec is used, then file ownership should be investigated as well .. log files /var/log/apache2/error.log or the like as well as the suexec log will provide information.
Since you're moving from Windows to Linux, you may also want to ensure that all of your paths work and are referred to in the same case ... I'd also go through your index page and verify whether all the paths actually exist ... for instance, this gives a 404 / not found : Further