'domineaux',
To obtain Dual-boot:
W/ 2 physically separate HDDs, as you have...
1 OS gets installed. Will show on C:\
2nd OS gets installed to the other HDD
Upon its (the 2nd) completion & @ boot-up there will a OS choices screen.
Whichever OS one is in will show as C:\
Boot is w/ the 1st OS installed.
If, @ the end of the day, seem to be boot issues, run Start-Up Repair w/ the W7 disc.
Regards,
Drew
"A scan a day keeps the nasties away!"