Inspiron 4000 Inaccessible Boot Device Error Problem

When I turn on my Inspiron 4000 with Windows ME, I get a blue screen with the stop error indicating an inaccessible boot device. I've tried numerous procedures found online with no resolution. I've have been able to use a floppy boot disk which gets me to the A:\ prompt, but I have no clue where to go from there. I took out the hard drive and inserted it in to my perfectly working Inspiron 2500 and did a Windows XP install. The hard drive booted perfectly the 2500 in to Windows XP, so I thought if reinserted it in to the 4000 there would be no problem.  Unfortunately, that didn't resolved the error message. Can I get some instruction on how to fix to the problem or problems I may have caused with the new XP install?

Thanks.