Originally Posted by willbushby
..the os on one partition say 20gb and have all the programs etc installed on the other...
Most computer savy people do it that way.
If you reinstall windows though, you'll still have to reinstall pretty much everything. Most programs have to interact with the OS, so when they "install" they have to make registry changes and/or modify the windows boot routine (to install their drivers). There are a few simple programs, like CPU-Z for example, that don't actually "install" (their "install" routines just copy their files to a folder).
Take it one step further, make Games, Programs, Overclocking, etc folders and install the appropriate stuff in the respective folders. You can even have Windows install put the OS files in a folder on the other partition if you want. There are actually just a few things that have
to go onto the first partition of the boot drive.