This has been hounding you that long? I wouldn't even waste the time trying a fast fix but have performed an upgrade to repair or full clean install if no system image had been created to resolve it.
The present problem of not being able to jump start it suggests a corruption in the registry that's been ongoing. One of those methods may just be what you need to solve it unless another solution is found. Offhand however I would advise backing things up in case you need a fresh start.
In that comes about and once everything is back and working make a good system image if you have a second drive to work with(even external). The fast solution may work for this but could see other problems emerge later if the registry did suffer a pounding or you initially had a bad install of Windows.
On a new build to upgrade someone else here I made sure to add in a second larger storage drive for everything including a pair of 1)clean install image 2)frequent updated to be overwritten image along with the long term storage of files. In fact that just saw a blue screen when going for the long list of updates with even the clean install.
You can still run Windows normally but will continue to suffer especially if something else comes up and there's no notification seen. That could even be a hardware problem leading to something worse if not seen to. This is why the notification service can still play a vital role at times and needs to be running.