Hello GF,

I think you are talking about "System monitoring in runtime", one of the innovations in WinCC Version 6. Critical system states, e.g. low memory space on the hard disk or low CPU idle time, are automatically monitored and signaled.
I agree with you that it should be possible to monitor the percentage value of free hard disk space.

Right now I don't know how the monitoring is done for memory space.
The documentation remains silent...... [:mad:]
Personally I think your message is raised if the free disk space is lower than 80% of total capacity.
You should forward this issue to Customer Support and ask for detailed information or a problem report.