If you do that you will be safe AS LONG AS YOU DO NOT MAKE THE MISTAKE OF FORMATTING THAT DRIVE TOO.  What you MAY have to do after installing your operating system (on the correct drive :) is run your Carrara, Poser, etc in the compatibility mode probably XP latest update.  That is a no brainer, just go down the list click on it and follow instructions.  You just have to do it once for each software that DOESN'T work  just quite right.  After that each time you click on the software, it will automatically come up in that mode.   One way of determining if you may have to do this is read the specifications, if it mentions Win 2000, ME, Xp but not Vista, examine all your software functions, can you still use them, are they flaky etc.  Jan