PECTool software will help you average multiple runs of Periodic Error Correction to better correct errors from the RA worm gear while avoiding transient errors from wind, environment, or tracking/guiding issues that affect a single worm cycle.  Training your mount with PECTool will allow you to get the best tracking performance possible from your Celestron mount. While Celestron has a goal of updating PECTool in the future, this is an older program with some limitations.  It is specifically designed for Windows 7 and earlier. Therefore, it needs to run under Windows 7 Compatibility mode on Windows 10—both when installing the program and again on the program itself.  You can download it from this [url=http://software.celestron.com/installers/?dir=PecTool]link[/url].  PECTool 1.0.18 is the most current version and is the one you should choose.  To enable Compatibility mode, right-click on the downloaded install file, click “Properties,” and change the mode on the Compatibility tab to Windows 7.  Please follow the same steps on the program file once installed on your Windows computer.