Tim here is what I do for my laptops and desktop. Create a partition for the OS and all your programs (C:). Create another partition for your personal files (D:). You may wish to have a third parition for backups (I only have a C: & D: on my three machines).
I see no benefit creating a partition for just the OS (different viewpoint Sneaky
), since any program will usually populate the Registry and often install files in the OS directory, Program Files directory, and so on. In other words, if you later reformat you will still have to reinstall these programs/games along with Win 7.
However, your user files stay nice and safe (though I always back them up before a reformat to an external hard drive just to be safe) on the D: partition. All you need to do after a reformat of the C: drive is to take ownership again of your user directory on the D: drive.
Of course you could image your initial install and load it back whenever you want to start fresh again, but given how quickly Win 7 installs I prefer to manually reinstall all my stuff. Btw Win 8 will have some neat features for reinstallation.
Before you reformat, obviously backup your important files, and calculate how much space you want to give each partition. My C: is 2/3 the hard disk space on my rigs with D: about 1/3. Obviously everyone's needs will be different; take a look at your current disk usage as a guide. If I remember you need to know the space by MB (I think). Do a custom Win 7 install, when prompted delete any existing partitions in order to create just one partition, do a quick format of that, then create your two primary partitions (C: & D:) - or how many you want. Win 7 will automatically install to C: (provided it is large enough of course). After the installation you can move your C:\Users folder to D:. Do this right away to ensure your programs use this new location. If you have Steam this must be installed on C: (with your OS).
Remember that nowadays partitioning, though folks will argue otherwise, really is not about performance but rather data management. Of course with any SSD there is zero performance improvement as it can retrieve data at the same rate anywhere on the disk. There may be a small performance boast by installing the OS first (on the outside of the disk), and some suggest getting a second hard drive and installing your OS and programs on drive 1 with the virtual memory and user files on the second one. I only have single drive machines myself.
Hope something here helps. Don't forget to backup your input files for ROF. With the new configuration, not sure what files we need to backup with regards to our input maps. Anyway.
TS!