blue candy, Is your entire drive on the slave used up as one big partition? If your only partition on the slave drive is using up the entire disk, then you're going to have to use something like
Partition Magic, which allows you to create, resize and merge partitions on your hard drive without destroying data. Then you should be able to create a second partition on your slave drive and install the OS there. That is just one option, there are other partitioning tools out there as well.
That's why is always important to backup your data. If you need additional help, you can reach me at
ResourcePC.
Dave