Boot from external hhd

[aceuk007]

I have a 21.5 imac late 2013. I have just replaced the power supply and thought while the screen is off I'll replace the hdd with an ssd.I have bootcamp setup on the hdd partitioned with win7. So I was thinking of just having macOS on the ssd and keeping my hdd as an external.
My question is can I boot from the hdd drive with macOS and win7 already setup on it enabling me still to access my win7 partition.
Thank you.

 

[apostolosdt]

I routinely run macOS from external drives, but I use only SSD for the latter. I doubt a platter drive will work, but I'm curious. Please, let us know if you succeeded.

 

[aceuk007]

OK. Thanks

 

[Nguyen Duc Hieu]

I have a 21.5 imac late 2013. I have just replaced the power supply and thought while the screen is off I'll replace the hdd with an ssd.I have bootcamp setup on the hdd partitioned with win7. So I was thinking of just having macOS on the ssd and keeping my hdd as an external.
My question is can I boot from the hdd drive with macOS and win7 already setup on it enabling me still to access my win7 partition.
Thank you.

You will need a little trick to run Windows from an external disk. It's possible but not officially supported by Microsoft. Their WindowsToGo solution had been offered for a very short time before being shut down.