Deleting partitions

I have a standalone PC with 4 partitions( total 20 gigs, c: d: e: f:). Primary partition c: is 3 gigs and running out of space. What happens if I delete f: partition? Will it increase the size of the primary partition. I am not using Partition Magicbut would like to use XP Pro’s partition program. Would I lose data in the C: drive?