Well its telling you that the file php5apache2_2.dll is not a valid win32 dll.
Now that should not have changed if you have not been playing with those files so quite possibly that file has become corrupted.
A disk corruption could also explain your original file privilage problem as well.
You could try downloading that file from the php site and replaceng the current version.
Or maybe it would be simpler to:
save all the files in c:\wamp\www and below i.e. your website
backup all your databases
uninstall wamp
reinstall wamp.
Of course you will not be able to use phpMyAdmin to do the database backup.
If you are still able to start MySQL from the wamp manager try downloading MySQL Workbench (its free)
[
dev.mysql.com]
Its a great tool for managing and querying mysql databases ( much better than phpMyAdmin )
Do the backup using that and then do the wamp uninstall and reinstall.