I do this all the time. Since Ubuntu is based on Linux, which means it is hardware independent (A whole different story if we talk about Windows) you won't have a problem in most cases. So since it is hardware independent you can just change your motherboard, cpu, ram, video card, lan card, wifi card and any other hardware without any problem.

The problems that will appear are (I will list some of them since you will get an idea with the couple I will write about):

• Hardware that needs Proprietary drivers - If you happen to move from a integrated video card in your motherboard (Let's say an Intel video card), to another computer with an Nvidia or Ati card, you will most likely need to install the proprietary drivers to have full features for that particular video card. Is not the same performance to compare the open sourced Nouveau with the Proprietary Nvidia drivers. Both of which are found and available to install when Ubuntu starts. This will likely not interfere with Ubuntu but will make it tough if you want to play son HD video or play a Windows game on Wine. Same goes for Wireless cards like the Broadcom Based ones.




• Moving from 64 Bit to 32 bit (Backwards Architecture). If you have a 64 bit capable hardware with an Ubuntu 64 installed on it and you move to a hardware that has no 64 Bit support, you will receive some errors. The opposite is not true on newer systems and Ubuntu versions but it is recommended to stick with the same architecture for performance and stability issues.

In the cases you are mentioning, you won't have any problems whatsoever. To test this, simply remove your hard drive and connect it to the other PC. Then boot from your hard drive. You will notice that it will boot like it was running on that computer since the beginning.

Aside from this, if you are going to use more than 4GB RAM, I recommend going for a 64 bit version, although the 32 bit will still use the additional memory with its PAE kernel.