Windows XP x64 will not read my WDE1U4000 External Harddrive?

I have no idea what Windows XP x64 is. (6_6)
I’d tell you to put Ubuntu on the malfunctioning comp as well and get the Windowsery over with altogether, but then I don’t know what you use it for.

XP x64 is known for it’s poor driver support. Since the HD works with x86 and Ubuntu, it’s most likely not compatible with x64.

I highly doubt that your computer is malfunctioning. The drive is just not supported.

Oh, I meant “malfunctioning” purely in the sense of “not doing what it should be doing”