[Trisquel-users] Re : dual boot with two drives

[magicbanana]

If I remember well, the hard drive can be master or slave (some jumpers to  
adjust). I believe GRUB should be on the master drive (otherwise Windows'  
boot-loader is run).

However you may only need to switch the disks in the BIOS' boot order. At  
least, that is the first thing I would try.