Thanks Pistachio, but I'm afraid that just gives me a different error message:
C:\WINDOWS\system32>reagentc /disable
REAGENTC.EXE: Operation Successful.
C:\WINDOWS\system32>diskpart
Microsoft DiskPart version 10.0.19041.3636
Copyright (C) Microsoft Corporation.
On computer: TONY-XPS-DESKTO
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
Disk 0 Online 931 GB 0 B *
Disk 1 Online 476 GB 14 MB *
Disk 2 Online 2794 GB 0 B *
Disk 3 Online 1928 MB 0 B
Disk 4 No Media
DISKPART> sel disk 1
Disk 1 is now the selected disk.
DISKPART> list part
Partition ### Type Size Offset
Partition 1 System 650 MB 1024 KB
Partition 2 Reserved 128 MB 651 MB
Partition 3 Primary 459 GB 779 MB
Partition 4 Recovery 990 MB 460 GB
Partition 5 Recovery 14 GB 461 GB
Partition 6 Recovery 1242 MB 475 GB
DISKPART> sel part 1
Partition 1 is now the selected partition.
DISKPART> shrink desired=250 minimum=250
You may not shrink OEM, ESP, or recovery partitions, or, offline volumes.The volume you have selected may not be shrunk.Please select another volume and try again.
Thanks for trying!
V/R,
Tony D.