Create disk container (like ISO) that can auto mount as RW

Question

Im looking for some windows program that can - create and mount large disk containers, like ISO files - must be read and writable - can be run as a daemon

Encryption is not needed. I suppose I could use truecrypt for this but the Encryption creates some overhead I dont need.

Edit, Im using windows 2008 Server R2

Answer 1

Mount a VHD. You can use the GUI tools, or diskpart allows you to automate the effort:

DiskPart 
Microsoft DiskPart version 6.1.7100 
Copyright (C) 1999-2008 Microsoft Corporation. 
On computer: WIN7 
DISKPART> create vdisk file="C:\vdisks\disk1.vhd" maximum=16000 
DISKPART> attach vdisk 
DISKPART> create partition primary 
DISKPART> assign letter=g 
DISKPART> format

Note that it might be visible across all sessions on the computer, not limited to the service account.

Answer 2

Assuming you are using Windows 7 (you don't specify) you can use VHD files, see this Wikipedia Page