I have a PC that does not detect the hard disk in the bios. I have to switch off the PC and then take out the power cord for about a minute and then put the power cord back in and switch the PC on. The bios then detects the hard disk and windows will then boot up ok. It seems to be happening alot since the weather has gone colder? Any ideas why this is happening?
Taking out the power cord for about a minute? The main difference that makes is to remove the 5V standby. This is the power that keeps the CMOS and other motherboard functions alive. Resetting the BIOS via the reset link or, as suggested by Trackrat, replacing the battery might be the cure.
HDD not always detected in BIOS As drives get older, they can take longer to get up to speed and become ready (available). This can then exceed the time it takes for the booting to look for the drive - so it doesn't find it. The solution is often to make the initial part of the boot take longer, by disabling "Quick power on self test and/or making the system look for the floppy drive first by enabling "floppy seek". Some BIOS even have a facility to put in a delay before the hard disk is checked.