Hi Andre. I was referring to the red bar denoting the disk space availabe on the D: drive I don't compress drives the performance hit is not worth it. (these days you don't generally need more disk space as TB drives are common) However the OP has obviously deleted several screenshots (assuming he took them) that is 2 and 3. The free space on what he calls "New Volumle" <I'd have labeled it different than the disk manager default - like Virtual Machines or even Windows Server 2003 VM>. Whether the drive was compssed or not after it filled up (an attempt which will fail with the 9% free he has - same error - not enough space) ) it would still show Red - he has not not said whther or not he got the Windows Low-Disk warniong. It appears s you can turn off that warning by editing the registry (or perhaps a third party progam might do it for you) but I serioulsy doubt he did this.
Anyway ther is no point in contiuing the thread until he replies to you, me or more fully to WoodyZ (I don't think he learned all about Treesize in a few minutes let alone the other programs mentioned
Guess we will just have to wait.