Launched in June, ThinApp 4.0 is the first iteration of the application VMware acquired through its takeover of ThinStall in January.

VMware's ThinApp gives enterprises a way of solving several tricky problems, including the age-old issue of securing Windows applications for users such as mobile warriors, onsite contractors or office visitors requiring guest access, by using application virtualisation.

Hardware virtualisation decouples the operating system from the hardware, while application virtualisation decouples the application from the operating system, a process which can sort out problems that can occur when IT managers migrate legacy desktop applications on to new operating systems.

The theory behind ThinApp is that IT managers can deliver conflict-free applications by encapsulating the application with all the components required to use the application, into what VMware says is a "virtual bubble".

ThinApp delivers the application as a standalone executable (.exe) or Microsoft Installer file extension (MSI), which should allow applications installed on Windows 2000 Professional to run on later Windows operating systems.

User data is stored in an application-embedded sandbox, or one which resides on a network drive, and is renewed after each application deployment.

We downloaded a trial evaluation of the ThinApp Virtualisation Suite, which consists of VMware Workstation (V6.0.4), together with ThinApp 4.0.

We installed VMware Workstation along with ThinApp on our Intel-based dual 3.2GHz processor system, which had 2GB of system memory, and created third-party application-free, fully patched virtual machines for Windows 2000 Professional, Windows XP Professional and Windows Vista Ultimate.

To create our packaged application, we used ThinApp to scan our clean Windows XP Professional OS.

We then installed Microsoft Office Project Professional 2003, and allowed ThinApp to rescan the system to capture the changes to the file system and the Registry, which defines an application installation.

When the scan is complete, the user can build the application depending on whether it is to be rolled out to a USB stick or a network drive.

After the files are copied on to the USB stick, the snapshot feature of VMware's workstation was used to roll back to a clean image of the operating system for which we were making executables.

We chose to deploy to a USB stick, and after building the MSI, we copied the executable and fired up the application on a standalone Windows Vista Ultimate system, with no problems.

At first glance the process appears complex, but that impression disappears after a few applications have been built and deployed.

In the full review to be posted later, we will look at the Active Directory-enabled application deployment, and the Application Link feature, which allows IT managers to roll out applications which have dependencies on plug-ins and the like.

We will also look at the Application Sync feature which gives ThinApp the ability to make applications which can pick up any service packs or security updates they need, without the IT manager having to use ThinApp to rebuild the entire application again.