I'm talking about this one:
Newegg.com - AMD Athlon 64 X2 5400+ Brisbane 2.8GHz 2 x 512KB L2 Cache Socket AM2 65W Dual-Core black edition Processor - Processors - Desktops
Flash your BIOS to the latest version before throwing in this CPU
Like I said, I'm a novice when it comes to updating computers. Are you sure I will be able to handle instructions and whatnot to reach and maintain speeds that the 6400+ gets right outta the manufacture? And any advice on memory?