Win7 reinstall

My 2.5yr old PC is getting slow, as HDD was full. I have installed a 3rd HDD and moved files, and wish to do a re-install from recovery disks.

I have done this in the past with XP on old PC, but want to know if there is there a quick way to get a list of programs, and maybe settings etc?
So that I know what to setup post win reinstall.

I also wish to create a partition after reinstall for windows and programs, can anyone tell me how to know what size to make it? Can I analyse my existing system to determine its size requirement?

Also, should and how do I update my BIOS, and when during the above?

 

OK, what size for partition with win7 and programs on, please???