I'm looking for software which will allow me to:
1. Record directly from my MIDI keyboard, (currently Roland 700GX) if possible retaining the voices (eg Piano etc) from the keyboard
2. View and print a score
3. Add other instruments eg bass guitar , or voice  How would I connect this?
4. Edit parts via the user interface eg to correct notes
5. Playback the recording without the keyboard connected.
 
I'm running a Win7 laptop with i7 processor.
 
 
 
 

All of Cakewalk's DAW software will do most of what you want. Try out Music Creator 6 or X3 Essentials, their least expensive programs. I think there is a trial version of X3 you can download.
I say "most" becuse no software can play a keyboard's sounds if the keyboard isn't connected, unless you record the sounds as audio.
So, record the keyboard parts as MIDI, correct timing and/or intonation problems, connect the audio out from the keyboard to your audio interface and set up an audio track to record and then click the record button.
Some folks say that the notation features of Cakewalk's software is pretty basic, but you can print out the MIDI information that you've recorded.