My Linux is running in a VM for which I allocated half of the physical amount of RAM (32 div 2) and 20 GB of disk space. 

I can see the structure of my disks. The 'linux swap' partition took 16GB. What was left (4GB) was allocated to the #normal# partition (ext4). I need to resize that 16GB swap partition to make room for the normal partition. 

I am a Windows user and would like a decent GUI app to do it.

I have tried gparted but unfortunately it won't help me. All options are disabled when I click the 'swap' partition.

It seems there is another GUI program called Logical Volume Manager, but I don't know how to start it.