Can you post your version of both security centre and virusscan?
I gather you are saying you turned scheduled scan off but it still starts correct?
Have you tried uninstalling then reinstalling following
reboot and run
reinstall from where your download is.
I suggest the reinstall as disabling scan should stop the scan starting so I feel it maybe corrupted. scheduled scan in versions 11.6 or better can be set to start on time not wait for the PC to be idle. the option is in navigation and general settings and alerts and general settings.
My virus scan version is: 15.0 last updated on 10.8.2012
My Security Center version is 11.0 last updated on 6.27.2012
The version of McAfee I have comes with my at&t sbcglobal account as my ineternet provider. I don't know if that affects a re-install, as I don't have a disk of the software.
You reinstall it from their site I think. Their version I assume is 11.0.678 the current is 11.6.? in the US and UK though Mcafee partners lag a bit behind. Maybe a reinstall of their current version could fix this. 11.0 has scheduled scan delayed if the PC is not idle. 11.6 fixes that or has an option to disable that.
I have a similar problem to skladder.
Why is it that despite having a planned scan set for a given time each week, McAfee nearlyalways seems to have a mind of its own and decides to start at some arbitrary time later - usually when I want to get back on the PC? At the planned time I always ensure that the PC (Vista SP 2) isswitched on, there are no applications open, the battery charger is connected and the energy saver is deactivated.
SEcurity Center 11.6 Build 11.6.434
Virus Scan 15.6 Build 15.6.231
It's not such a serious defect that I'd want to experiment with uninstalling and reinstalling, it's just that paying as much as one does for McAfee, I'd expect it to be free of sush irritating faults.