If you are using 4.1 SP3 - build 1574, and want to migrate to 4.4, you have to upgrade firstly to 4.2 and then either to 4.4 or go through 4.3 and then 4.4. You have two options for upgrading the website:
1. Copy and replace the dlls from a new project that is higher version then yours to your bin folder, and restart the application, so the upgrade scripts can be initiated.
2. Open the Project Manager, add your project there and hit the upgrade button. More information can be found here:
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items