Right, so my ghetto HTPC currently has one stick of 128b PC2100 (133mhz) DDR SDRAM in it...

Google info shows this up as being 184pin DIMM or something.....

Using the Memory Finder on Corsairs site, they suggest I should be using 266Mhz version of the above RAM....

Can I do that? Whats the benefit/disadvantage?

I was thinking rip out the 128 and stick in either 2x 256 or 1x 512 sticks.....