power saver mode
computer power save mode
Is this a question about power saving mode in general or something specific? You need to put in some information in the post to get assistance.
If you are saying you see a message on the monitor about it entering power save mode, that is from the monitor not the computer. Usually means there is no signal from the computer to the monitor. Check your cables and make sure the PC is turning on properly. Test the PC with a known good monitor.