can i move my Linux hard drive out of my dell 2300 and put it in my dell 4550.
the only difference i can see in them is 4550 has a micro processor and the 2300 dont. both cpus are about same speed.
Do you mean to boot from the drive as it is? I have done this myself a few times. The only problem I can see is if you have a different graphics card manufacturer - I mean NVidia or Radeon as they use different drivers
If it does not work, it will not hurt the hard drive. You can always re-install Ubuntu on it on the new computer.