The scheduled scanner will delay its start if the CPU is being used above a certain point but it shouldn't delay more than about 20 minutes. In your header you say real-time scanner wont start, that's a totally different thing, that means SecurityCenter would be giving a red warning.
Did you run the Virtual Technician? It can often correct minor issues. It has to be freshly downloaded whenever you run it so uninstall once run in the normal manner through Control Panel/Add or Remove Programs.
If that doesn't help then I suggest contacting Technical Support - it's now a free phone call as well as online chat. See the link under Useful Links at the top of the page.
Laslty, if you are running any registry cleaners or optimizers, stop, as they can cause this.
Everything ok now- misspoke- my problem was scheduled scanning not coming on- checked it out found automatic turned off- ran all my programs as suggested anyway to check for problems, found none. Last night came on as scheduled at 6pm- thanks for the answers and help-
That's good. All the best.