Ahhh!! Powershell. I try to avoid if I possibly can, but maybe, if it's the only way.
[Edit] Actually braved it, and ran the first bit of the Powershell, which tells me that RetainDays is 14. So does that mean that, even though I can't see it in the GUI, it IS doing what I want and removing stale VMs after 14 days? (I don't at this stage want to change the default of 14.)
Computer Manager at Bedford School, UK (since 1999).
Veeam user since 2009.