Hardware issue on startup -- CMOS Error

Hello -- on my In The Groove 2 Machine, when I boot up, I get the error:

CMOS Checksum Error -- Default Loaded. Press F1 to Continue, Del to enter setup.

Now, it seems like I can press F1 and continue playing, although I haven't tested this fully. (It loads the game, all my saved scores are loaded, and it all seems fine, at least.)

However, I had some questions:
- Would you have any ideas why this is occurring? I read online that it could be caused by a dead CMOS battery -- are there any other potential causes, and can this be checked?
- What battery would be used for an In The Groove 2 machine, and how difficult would this be to replace?
- What is the impact of this? From a practical level, I don't have a problem plugging a keyboard into the USB slot and pressing F1 every time I boot up, although obviously if I ever sold the machine, it should be fixed. Other than the System Clock permanently being 1/1/2004, are there are other concerns?
- I think I take good care of the machine; it's not played a lot, the fans work, and occurring I use an compressed air duster to ensure there's no dust buildup inside of the machine. Can you think of any other things I should be doing to avoid problems?

Any advice or comments would be appreciated.

It's not surprising that the battery may have died, it happens at different times for different computers. They're very simple to replace, just look for it on the motherboard, pop it out of its holder, then pop the new one in. Normally this will be the type to look for:

http://www.google.com/search?q=Maxell+CR2032+3V&hl=en&safe=off&sa=N&prmd=imvns&source=univ&tbm=shop&tbo=u&ei=o_RnT47dCo2DsAK9xsGRCQ&ved=0CKQBEK0E&biw=1280&bih=707

You can see where the battery is located in this video:

http://www.youtube.com/watch?v=y1yV4MPw8eQ#t=3m12s

How to replace the battery:
http://www.computerhope.com/issues/ch000239.htm
http://www.hardwaresecrets.com/article/81

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