well I was woundering if I could install a new version of windows buy using the hard drive as a slave drive in my desktop then put it back into the carputer and let it boot up, or do I have to bring in the carputer and install like that?
It will need all of the hardware information from your computer (drivers)... so it's best to install windows through the CD-Rom on the computer and harddrive in the CARPUTER
Yes you can do that. However, you will need to make it the only drive in the desktop computer at some point, so that you can set the active partition (I did this with my HDD for my mini-itx system).