Thank you for writing.
Vista is an old theme which we no longer support and this is why it is excluded from our ToolBox. It is strange that you have seen it in your Toolbox, because we did not add it there in our lastest version. Could you please make sure that you are using the latest version of our suite? If you are with the latest version of our suite, please remove all RadConrols for WinForms installations from your machine, download the latest version once again and install it.
I am attaching the project that builds the Vista assembly. Just include it in your solution, add a project reference to it and you will be able to use the Vista theme at design time.
A bit off topic, I would like to remind you that your subscription package has expired, which means that you can be denied support services. I would highly recommend upgrading your license to the latest version in order to continue getting product updates and uninterrupted support services. Please, contact email@example.com
or visit your account for your upgrading options.
Let me know if this works for you.
the Telerik team
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