anyone ever seen this ? a partition with a drive letter has sneaked its way onto my server 2022 PVS master image and no idea what it is

That looks like some 3rd party Dell tool. I recall that on my laptop years ago. I know you wouldn't use that, but that is where I seen it before.

i have read a few posts online about it being related to failed windows updates but the file always seems to be on C:\ in my case i have a seperate partition and drive letter F:\ assigned to it https://superuser.com/questions/1302986/what-is-this-file-winre-backup-partition-marker