Transferring everything to a new PC: can I simply swap the drives?

You could but you have to check if the new system is Legacy Boot or UEFI

Bert Coules said:

Thanks for the speedy reply. Which of the two alternatives is the one I would need? I'm guessing Legacy Boot but obviously I need to be sure.

The BIOS setting just has to match the drive.
If the drive is MBR, then you will need to choose "Other OS" in the BIOS.
If the drive is GPT, then you will need to choose "Windows UEFI" in the BIOS.


Open a command prompt as Admin and do this...

Diskpart

Then... List Disk


If the disk is GPT, there will be an asterisk in the GPT column.






Do you know the make/model of the motherboard in the "new" computer?

Bert Coules said:

I just tried that check: both the C: and D: drives in the existing PC are GPT. I don't yet know the motherboard details of the potential new PC, but I should be able to check today.

With the motherboard make/model, we can download the manual, and give you a screenshot of the correct BIOS setting.

For example... in MY motherboard's BIOS (Boot tab), I need to choose the settings in the RED box, to "match" with a GPT disk.
For "Boot Device Control" I can choose either of the two, for a GPT disk.






If the BIOS setting and the disk type don't match... it won't boot.

You can just move the C: drive over, and if the comp doesn't boot, go into the BIOS and change the settings, to match a GPT disk.
Ofc, in the description (in the BIOS), it doesn't "tell" you things like... this is for a GPT disk, or this is for an MBR disk.

That would be way too easy.

Bert Coules said:

That's great. I'll have the new machine this afternoon and I can check the motherboard settings and alter them if necessary. Many thanks again for your help.

You may run into activation issues. Even though you're moving the drives, you are technically using a different motherboard.
You should still be able to get it activated, but you'll probably also need to use the activation troubleshooter.








If you run into any BIOS or activation issues... there will be plenty of people here to assist.

Before you move the drives- and I hope you already do this- make sure you have a 3rd party disk image of all the partitions on the drives.

You do not want to suddenly find your one and only installation is suddenly useless and unbootable... so take due precautions.

Note that the Tutorials section is an excellent resource: so to determine if the O/S installation is legacy BIOS or UEFI you might have found this:
Check if Windows 10 is using UEFI or Legacy BIOS

There's a tutorial on the activation troubleshooter and much more there.. do feel free to have a look.

N.B. transferring activation is easier if your digital entitlement is linked to your MS account. (Tutorial available).

Note that if there are aspects of your installation's configuration that have led to your PC having become slow, some of these may still affect it when running on new hardware.

Sanity check: After a cold boot, wait a couple of minutes, then check resource usage is minimal (task manager).