Can anyone explain to me why I need to partition my HDD ?
and recommend sizes of partitions

I have a Samsung R20 120 GB HDD .

At first power up I am asked to partition the HDD int C drive and D drive

on D drive, a samsung recovery application is stored and this will be the place for future use recovery sets.

If I split the disc 50:50 then do I have 60GB for programs + files and 60 gb for back up ?

do I need 60 gb for programs?

Do I need 60 gb for back up.?

It has been suggested that I split it 40gbC:80gbD but store files on D, if i do this does this mean only the contents of C are 'safe', in this case what happens to the files on D if there s a problem ?

I'm confused...

use will be for Ms office applications with dowloads, music/vid files/ pwpt pres with phts etc.

Partitioning is mostly a 'personal choice' thing, depending on many factors like disc size, types of files you're working with (mostly for organization), but the biggest reason some people partition is because they run multiple operating systems. It's almost a necessity to put each operating system on it's own partition.

Here's a couple of articles explaining partitioning further.....

Why partition? - 1

Why partition? - 2

With a terabyte of drives on my system, partitioning is a must.....

WARNING - If you fool with Samsung's recovery partition you will loose the Samsung's Recovery option. It is their method of complete recovery if your C: goes south.