When my PC is booting up, it stops mid-cycle with the message:- 'Detecting IDE drives...CMOS checksum error - Defaults loaded'.By hitting Ctrl Alt Del then Esc a few times then F6 followed by F10 I've managed to get it to start. Then one other time, I'd disconected the computer to take it to a repairer's then reconnected it up again and when I switched it on I didn't get the earlier error message but it's just that the Windows XP logo stayed on my screen for a couple of minutes before the machine booted properly and all my icons came on the screen as usual. Can someone suggest a reason/cure?

Hi eddk,It seems to be that the CMOS (Complementary Metal-Oxide Semiconductor) battery is faulty.I would recommend you to replace the CMOS battery and check if the issue persists.Note: Modifying BIOS/ CMOS battery incorrectly can cause serious problems that may prevent your computer from booting properly. Microsoft cannot guarantee that any problems resulting from the configuring of BIOS/CMOS can be solved. Modifications of the settings are at your own risk.Hope the information helps. Please post back and let us know.RegardsDebleena SMicrosoft Answers Support EngineerVisit our Microsoft Answers Feedback Forum and let us know what you think.

Thanks. Is this a job that a beginner can fairly easily tackle would you say Debleena?

Hi eddk,If you are not comfortable in doing this, I would suggest you to contact any local tech shop who will be able to assist you in replacing the CMOS battery. RegardsDebleena SMicrosoft Answers Support EngineerVisit our Microsoft Answers Feedback Forum and let us know what you think.

Actually the fault just stopped. I had seen somethng somewhere where someone said they encountered the problem only in cold weather. Even before I brought more warmth to the room where my machine sits the difficulty stopped - for over a week. It started up again in the last 2 days so obviously it needs actual attention. Thanks