|Your motherboard has many features that you need to read about. |
There are jumpers and DIP switches which I assume you have not disturbed.
Your board can use 2 different types of memory modules but not at the same time. If your memory is installed in the bank of 2 memory slots you are using DDR memory. If installed in the bank of 3 then you are using SDRAM.
Your board should be set to automatically detect the proper settings. There is a jumper to over ride the automatic detection
The correct settings for an Athlon XP 1900 are 12/100/133 with 1.75V vcore.
Below is a link to a downloadable copy of the motherboard manual. I suggest you download it and save it to CD. Review it and verify everything is set for auto detect.
Read about the BIOS setup starting at pg 50. Pay special attention to AGP settings as they can cause stability issues.
I suggest you try 12 multiplier and 100 FSB. Your RAM may be too slow for 133.