Not a lot of information to go on.
Pressing F1 to continue boot generally indicates hardware changes or problems. Or that the CMOS battery is getting weak.
If your BIOS boot is slower than normal I would replace the CMOS battery.
Others will follow to clarify and correct.
I have a P4 system with win.XP operating system which has been working fine for last 2 years.Now after the Bios check is completed is asking me to press F1 key to continue. I do so, the windows starts and everything is Ok after.I would like to know how to get rid of this error.