When I am already logged in and then run CC manually it completes in about 5 seconds. I also have it set to run automatically at computer startup but it appears to get stuck at 3% and then takes from 30 to 60 seconds to complete. Any reason for this, please?
The system startup sequence perhaps. You'll have Windows doing it's Windows thing, and also security software such as an anti-virus/anti-malware since many of them take over doing an initial self-check and system startup scan to make sure there's no infections in critical system areas.