I disconnect all HD's and SSD's EXCEPT the one i am installing the OS on.
So, disconnect all HD's except the 160 where you are going to install Win 7.
If you have errors installing Win 7 with only the 160 HD installed, post back with specific error messages.
If you don't have errors, does Win 7 boot up after the install?
I'm no installation expert, but that is what i do.
You can also wait for advice from an installation expert before doing anything.
Gregrocker is the best installation expert i know of...
best of luck,