IN THEORY, 2008 is very hardware independent. However, I believe problems can still occur if any of the following is true:
1) you switch processor architecture (go from x64 to an x86 only system)
2) you switch processor architecture (go from AMD to intel or vice versa)
3) don't have necessary disk controller drivers installed that support the new disk controller prior to making such a transfer.
If you had done this in a virtual machine, it would have been easy to switch.
In addition, knowing the error messages you received and the hardware you went from and to would have been helpful to understand why things didn't work.