What version of OS is the Time Machine copy from? If it is 10.7 or later I would start by pressing option when I boot and select the recovery partition. Then I would try disk utility and verify the disk. Once you have either verified the disk is fine or repaired it after being told it was not fine I would repair permissions.
If that doesn't help I would then do a fresh install of the OS and and either restore again, or manually migrate the data from the Time Machine backup. To be honest, I would almost certainly just do a fresh install of the OS myself but that's a choice and not a necessity to start with.
Report back if you have questions or this is not helpful.