New iMac won't boot into Lion

[seble]

Have Lion on an external HD, and a piece of software is playing up on this imac so wanted to boot into lion.

When I select the Lion external HD as bootup disk it just comes up with a barrier symbol on the screen (circle with line across it). Does that mean because my machine shipped with ML, it won't boot Lion?

Thanks

[simsaladimbamba]

If it is a late 2012 Mac, yes, as Mac OS X 10.7 Lion does not contain drivers for such hardware. If it is an early 2012 Mac, you need 10.7.5 on the external HDD to boot from it.

[maflynn]

On Macs the lowest version of OSX you can use is the version that it came with. So if you're trying to boot into an older version, i.e., 10.7, then that will not work

[simsaladimbamba]

Originally Posted by maflynn

On Macs the lowest version of OSX you can use is the version that it came with. So if you're trying to boot into an older version, i.e., 10.7, then that will not work

Though there are exceptions, like the late 2011 MacBook Pros for example.

[seble]

Originally Posted by maflynn

On Macs the lowest version of OSX you can use is the version that it came with. So if you're trying to boot into an older version, i.e., 10.7, then that will not work

Originally Posted by simsaladimbamba

Though there are exceptions though, like the late 2011 MacBook Pros for example.

Thought that would generally be the case. Oh well, I'll have to think of something else. Thanks guys.