Need to press F1 every time

What message do you get? Is it a Dell by chance?

Yes this could be caused by a number of reasons, have you recently modified the hardware? Added or removed a hdd or ram. Sometimes computers will have a warning message that pops up if the case was previously opened etc. Without the error message that comes up it could be a million things.

Please post the error message and we can help you better.

I have a Dell Latitude D610 that displays a message upon boot that the power adapter cannot be verified, or something in the ballpark. What it means is that the power adapter's signal didn't get through to the notebook to verify that it's a genuine Dell part. Is this the message you're receiving? If so, I have a workaround, but the only solution is to replace your adapter.

Best Regards,
Martin Schultz

Thanks all for replying me very quick,

After installing new OS, I am getting this alert.  but although I need to check what recently added to this computer.

First to try is to replace cmos battery.

the message refers tin most cases to a change detected by the bios
it can be caused by a low battery too; it should read 3 V; or replace it CR2032 model

also - it may go away if you enter the bios, and save the changes

I would like to leave this question

what exactly does it say when it asks you to press F1?

>>  I would like to leave this question    <<   why? give some feedback to people trying to help you

then pleas e close it; if you don't know how, read the help files

Switch the system on then immediately press del key, this will open BIOS setup, go to an option says save and exit, hope that helps.