A PC techie told me that my TNT2 M64 video card is overheating and that is why it is causing horizontal grey lines on the screen behind every line of text. I am thinking of using the video card until it is spoilt. Will this cause any damage to the motherboard? I am also thinking of changing the 3 year old battery in my PC. What is the best way to prise out the old battery?

If I were you, I'd replace the video card ASAP. As for your second question, I'm not familiar with the word "prise." Do you mean remove? If so, just pop it out. It's simple..Just remember you may lose many of your Hardware settings if you do this. If you're having no obvious problems that you can attribute to a bad battery, I'd recommend just leaving it in.

You should certainly get much more life than 3 years out of your battery. When it starts to actually go, your computer will merely lose any data which it stores in your BIOS, so you will lose personal preferences there. I work on many computers which are 10 years and older which still all have their original batteries---I have only had to change 2 in various computers in 15 years! Video card --- do you see any problems when working around in Windows using your mouse. I think that if the video card was having problems, it would have problems displaying graphics while in Windows. It could also be a keyboard problem. See if you have problems typing text before your computer goes in Windows (press your F8 key and go into "command prompt only" and try typing text there). If your video card is PCI, you could also try inserting it into a different PCI slot on your motherboard.

horizontal grey lines are ussualy cause by some bad video RAM. Nothing that big to worry about if you dont mind dealing with the lines. (if you dont mind the lines run it till it blows, if its under warrenty get it replaced.)