PC is unable to start right after electric switch is on. Boot process is started, but it stops. When I left it for 4-5 minutes and try it again, after push power button, it works properly. I can start it again more times, if I left electric switch on.Yes. That is a valid observation and typical of desktop computers.
The makers of such machines say you should leave it on all the time and only use the operating system to shut down the computer.

Did you have a QUESTION? Geek, you answered a different question from the one asked. OP is asking about starting computer. kovacsa, do you live in a place with unstable power? POSSIBLY voltage takes some time to stabilise after switch on, especially if you have big loads starting such as refrigerators, air conditioning etc.After reading his post again, I get the same idea it got the first time.
He turns off the power from a external switch of the electrical main.. hen he turns the switch back on, , the computer will not start until he waits a bit and then hits the push button.

In some computers there is a BIOS setting to change the behavior for power loss. But the computer makers do not recommend the user use an external switch to turn the computer off and on.

Please explain it to me again. What did he do?I always shut down the PC using the 'shutdown' option in the Start menu, then after that when it has all gone quiet I may well disconnect the AC cord from the wall outlet (in Britain they have a switch). I am supposed to do this when leaving the house for more than 14 days (it's in the fire insurance).

If the OP was shutting down just by removing the AC power, then all kinds of bad things can happen, including file system corruption and maybe hard drive damage.
To be more specific: I use shutdown option, after that when it is successful, I remove AC cord from wall outlet. A few hours ago I put AC cord back and press power button on computer. Boot process is started, but it stops, computer shutdown automatically. If I wait a few minutes after I put AC cord back, it works perfectly. Power seems stable, there are another PCs in house and are working correctly.OK, you need to check the CMOS battery to see if it has lost settings.
Your PC may have nighttime, but some settings may have been lost if the battery is weak. This is often a small coin-size cell with number 3002 and should be 3 volts.

There is a setting about how the PC responds if there is an apparent lose of power. The wrong setting may cause the odd behavior.

When the PC is off it still monitors the AC power. I have a PC also has behavior when I turn the power strip back on. Like you, I shutdown the PC the normal way and then turn off he power strip. I just pit up with it. I use the default settings.
Cé La Vi It has cell button 2032. But how comes it? Could this BEHAVIOUR caused by this battery? Why is it working correctly after a short period of WAITING time?Quote from: kovacsa on September 14, 2018, 01:33:35 AM

It has cell button 2032. But how comes it? Could this behaviour caused by this battery? Why is it working correctly after a short period of waiting time?

It has cell button 2032. But how comes it? Could this behaviour caused by this battery? Why is it working correctly after a short period of waiting time?