Although it is recommended elsewhere to disable System Restore when infected, personally I wouldn't. The logic is that SR, when it creates Restore Points, may back-up any infections that are present and disabling SR will remove these infected RPs. While this is true, unless you use SR and choose an infected point there is no risk to your PC.
The greater risk to you is that something goes wrong during a removal attempt and while normally you could give SR a go to see if it will undo the oops that has occurred, if it is already disabled it won't do any good.
Leave SR alone and fix any problem you have. If something goes wrong, then run SR and hope it puts it right. If nothing goes wrong, create a new, clean, Restore Point and call it something that will enable you to identify it and do not use any RP from before this time. Eventually SR will run out of space and delete the oldest RPs as it is programmed to - this will eventually delete any infected points and all is well with the world.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You don't say what file(s) Norton is detecting as tidserv, but if it is c\Qoobox\Quarantine\c\windows\sys32\driver\atape.sys.vir you don't have an issue.
The location is where ComboFix stores back-ups of any files that it removes, just in case they are needed for some reason, so it is an old infection. CF also adds a .vir file extension to the file, which further disables it to leave it as nothing more than a reminder of what you once had on your system.
Simply delete the file as you would any other and find something better to do with the rest of your evening.