Many times, shutting down the power from the powersupply (or unplug the pc) for 10+ seconds (20-30) to be super safe and that might be able to help you boot.
or the better way is just to use the reset jumper like the previous post said.
If you can't find your manual, and really can't boot at all, the last resort is the take out the batteries on your motherboard for a couple of seconds and then put it back in and that will reset your bios as well.
You should really look up what motherboard and ram you have, for us to be able to help you. Most of the time the ram will have a sticker telling you what speed it runs at.
Motherboards don't always tell you what model your using. If your lucky, it should be printed right on it. Otherwise, finding what chipset it runs and what manufacturer (msi maybe?), you can narrow it down quite a bit from their website.
Anyway, I also have a duron I want to overclock. I don't remember exactly what model my board is either and don't want to look it up right now cuz i'm at work (shhhh), but its the asus board with the nforce chipset. Its not the full size board but the one for the mini-towers. I have pc2100 ram in it and its an duron 950. Any ideas. I don't seem to get any overclocking options, so maybe its just the board.