How can I test windows programs in the cloud?

I'm working on a project that makes heavy use of shell extensions. I want to test it in as any versions of windows as possible. Is there a service designed for this? Almost like a VPS host but with OS images for retail XP, XP SP1, XP SP2, etc

How do I test my application in the cloud?

One approach to cloud testing includes the use of specific tools for individual tests, such as performance testing, load testing, stress testing and security. Another option is for organizations to use complete, end-to-end testing as a service (TaaS) products.

Does Windows 10 have a sandbox?

The Windows Sandbox is a temporary virtual machine built into Windows 10 and Windows 11 that allows you to run software without it affecting the rest of your system.

I'm not sure of any services like that, but it sounds to me that you want to use a virtual machine such as VMware or VirtualBox.

You can use Windows Azure VM Role to get your VM setup in the cloud. On the VM you have to install all the required softwares. Coming to your point, If you look at http://www.microsoft.com/VHD, you can get trial VPCs for your use that you can then either run on your own machine or host in cloud.