Score:0

how to use a dual boot UEFI disk in a Legacy PC?

my flag

I have a dual boot(windows10/Ubuntu20.04) disk that is UEFI. I want to use it in a Legacy only PC. Is this possible, short of wiping and re-installing?

ChanganAuto avatar
us flag
No, not possible. Windows specifically requires MBR for BIOS/Legacy mode (and conversely GPT for UEFI mode as it is now). There's no way to perform such conversion.
cn flag
In Linux it is possible; Windows I would assume too: you can switch from legacy to uefi by adding uefi; the reverse should be possible too. A reinstall is easier and less error prone ;) Example for Linux: https://unix.stackexchange.com/a/403275/10017
cn flag
and the off topic part of your q: windows up to 10 -> https://appuals.com/convert-uefi-to-legacy-bios-on-windows-7-8-and-10/
oldfred avatar
cn flag
Windows will not boot from another system drive as it is licensed to only one system. But drives are low enough in cost, to just use another drive. And do a full install in BIOS boot mode. I still would use the newer gpt partitioning, but then you need a 1 or 2MB unformatted partition with bios_grub flag. I might also keep an ESP on that drive also, so it could later be easily converted to UEFI boot. Then just restore all your data from your normal backup to make it identical to UEFI drive.
mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.