Most likely if it is Norton that is the culprit, then uninstalling Norton Antivirus software and then rebooting it will enable 'System Restore' again. It's something to try if you're already 'doomed' to reinstall NAV after your system restore. Of course, it could still be the culprit, and it's 'broken' your System Restore.

Try that, and if it works, then use some other antivirus that won't start nagging you and then 'expire', like AVG Free Edition.

If it doesn't work (and you don't need to restore right now, or have already restored successfully), try disabling and re-enabling 'System Restore'. You will lose all previous restore points, but there's a decent chance that the new ones henceforth will work.

Good luck. There's already a small chance NAV has mucked your computer up, so uninstalling might drop the bomb on the system so it won't boot again. Be sure to make a fresh System Restore 'snapshot' before you do it... assuming that snapshot can be restored.

If you have a full license or recently got your computer with this crapware bundled in it, you might be able to get some free online support from Symantec or your computer manufacturer.

A lot of people on this Forums hate Norton because it is a resource hog and altogether not very effective. I myself had to have an IT friend of mine uninstall it, 3 times and that was AFTER the Geeks at Best Buy had already uninstalled it for me, per my request.

You can get the Norton Uninstall Tool from this link http://service1.symantec.com/SUPPORT/tsgeninfo.nsf/docid/2005033108162039 just follow the prompts.