Thank you for writing.
To upgrade to the latest version you can use one of the tools you mentioned (e.g. RadControlsForAspNetAjaxControlPanal_2012_2_607.exe) because they both launch the new Telerik Control Panel. With the aid of this tool you can install the latest version of RadControl for ASP.NET AJAX and Telerik Reporting.
After you have installed the latest versions you can use the Upgrade Wizard
for upgrading the RadControls for ASP.NET AJAX projects. Regarding the Reporting projects, please, follow in instructions in the following article
For setting up an environment with the 2009.2.826.35 version you should download the Q2 2009 SP1 versions and perform a pure install on your machine (no hotfixes should be considered). Here are the links of the previous versions pages for ease:
RadControls for ASP.NET AJAX
I hope this will help. Let me know if you need any further assistance.
the Telerik team
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