How to shrink Win7 pvm disk size

Hello,

I have a Macbook Pro with a 250gb SSD hdd. I am using Parallels 7.
I created a windows 7 virtual machine and gave it 64gb expanding HDD size. Now my mac hdd is getting low on space.

I see in 'about this mac' -> 'more information' -> 'storage' that my disk is 250gb in size, ~9gb space free and then there is this 64gb which is yellow and described as "other".

The .pvm size itself is 19GB and in win7 it's showing me the same disk usage out of 64gb. So I powered down the machine and shrank the disk size from 64 to 32GB, but it did not free up more space (in win7 it showed me 32GB as the new hdd size), it still shows 64GB as other and 9gb as free under macOS.

I also tried the 'compress' option in parallels but it showed that only 4GB of space would be freed up (19gb -> 15gb).

How can I shrink the 64GB that parallels is supposedly using ? I tried reinstalling Parallels but it did not help. I would not like to delete my win7 pvm, because it's configured as a domain machine.

I'd appreciate the help!

tldr; win7 pvm is 19GB but parallels is using 64GB of macOS ssd disk.