I recently purchased a Lenovo mini tower server. I have an old system that died on me. The motherboard seems to have gone out. I wanted to try to add the hard drive to my new tower and boot from it. The thing is it runs off of Windows 7. From what I've read, Windows 7 runs off BIOS and my system uses UEFI.

I've selected the Legacy Only option and I've tired identifying the hard drive as the boot device, but it only barely gets to the starting windows screen before it restarts.

I think I'm woefully out of my league, but any advice on how I might be able to get this working would be appreciated. Thanks!

  • Windows Vista/7 also support UEFI boot. How is the old system booted? In BIOS/CSM or UEFI mode? Jul 12, 2016 at 4:46

1 Answer 1


From what I've read, Windows 7 runs off BIOS and my system uses UEFI.

On, no and yes, mostly no.

  • Windows 7 can be installed using a classic firmware (BIOS) with a disk partitioned with MBR.
  • Or you can use the more modern firmware (EFI) and use a GPT disk.

You cannot swap between those. Installing in MBR mode and then moving to an EFI setup will not work. Neither the other way around. Use whatever settings you used for the old setup.

Note that many modern EFO firmwares support a legacy mode. This is likely what you enabled when you selected the Legacy only in the EFI.

A second no because moveing an installed windows OS from one computer to another is not likely to work if the hardware is different. Windows tries (and is) smart about hardware and does some smart things in order to boot fast. But that also ties it to some hardware.

This comes down to:

  1. Either it will not work (e.g. when the HDD controller for the old system was different and the new controller is not recognised. So windows canot boot until you replace some drivers. Which is a catch-22
  2. Or it will work and you end up with a system which needs massive updating.

Option 2 is likely to be accompagnied with needing to activate windows again (and hopefully you bought a full license in a shop for a windows version which allowsyou to install it on another computer. Moving the license from the Lenono setup is likely not allowed if it is a Lenovo OEM license).

And maybe to late for this time, but for completeness sake: It is possible to move windows between hardware. Usually this is started with sysprep which cleans out old drivers, sets compatability drivers etc. That is not an option unless your old system is still running since you need to do that before moving the disk.

  • Thanks Hennes! This is kind of what I assumed. I was hoping to be tricky and see if it would install with the new system without any trickery, but alas, it was not to be. I should still be able to get to the data on that drive once I install a new OS, right? Jul 13, 2016 at 15:48
  • Yes. EFI vs MBR us just modern partitiong style vs ancient (1980's era) style. Once you have a partition it gets formatted with a filesystem and then mounted as a volume. Those last two act the same, regardless of partitioning scheme. You could even add an MBR style DATA disk to an EFI booting system. Just make sure that the OS bootdisk and the installed OS version match. Anything else is mix as you like.
    – Hennes
    Jul 13, 2016 at 15:57

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .