I had written to the forum previously about the same subject, but I suppose I am apprehensive about purchasing a new HD and have it not work in my machine. I am considering the following to replace my 40Gb: Western Digital Caviar SE WD800JB 80GB 7200 RPM 8MB Cache IDE Ultra ATA100 Hard Drive. I have a XPS 410 and a Dimension E521, so I don't need a larger HD. My question: Is this HD compatible with the 4300? Any help appreciated.