[WOLFGIR]

Well first of all, you usually have to IDE ports on your puter.
Make whichever of the harddrives the primary one in the first port.

If you use an internal CD-RW, make that one the slave of one harddrive, and the cd/DVD slave of the other, keep the two harddrives as the primary ones on both ports so to say.

CDRW and CD on to different ports makes it more reliable in copying or direct burn cd to cd..

When you have decided which harddrive to use as primary, do a new install on that one, reformat it, make it legal and everything. Then start it up, clean the one that is the secondary drive and start installing and do the backup progress and offer a prayer to the god of caffeine and you SHOULD be safe and sound.

Installing a second harddrive is easy, if you do it correct from the beginning and don´t start messing with the boot up and everything that is usually the case when you want to switch from on to the other...