I really don't know what I have but I went to Crucial's website and told them what motherboard I had and they told me what I needed which is what I listed above. I can't tell what brand is in my computer now but there are two sticks of 256. They say on them DDR 266,PC2100 and 32x64. Below is what Crucial's website came up with when I put in my motherboard.
System Specs:
184-pin DIMM Banking
3 (3 banks of 1)
Chipset
VIA Apollo P4X266
DDR SDRAM Frequencies
PC1600 and PC2100
Error Detection Support
ECC and non-ECC
Graphics Support
AGP 4X
Max Registered DDR SDRAM
3072MB
Max Unbuffered DDR SDRAM
3072MB
Module Types Supported
Unbuffered and Registered
Supported DRAM Types
DDR SDRAM only
USB Support
1.x Compliant
