Test Design Studio stores license information locally on your computer. To prevent license circumvention through manipulation of this file, the licensing system closely monitors this file on the disk.
There are certain situations where the license file on your machine gets "moved" on the disk. This creates the illusion that someone might be trying to alter the license file or restore it from a backup after the license has been deactivated or otherwise invalidated. When this happens, you will be prompted to reactivate your software.
Under normal circumstances, this situation will not happen without a user actually moving the file. When it does happen, the most likely scenario is that a File Defragmentation program is moving the fragments of the file around on disk and causing this situation. Many File Defragmentation programs allow you to exclude certain files. If this is your situation, try excluding the TestDesignStudio.exe.ldat file (if it exists for your version of the software) or any license files (*.lic) that are stored in the installation directory of Test Design Studio (i.e. C:\Program Files\Patterson Consulting\Test Design Studio\TestDesignStudio.exe.ldat). These files may be marked with Hidden, System, and/or Read-Only file attributes, so it may be hard to see in Windows Explorer. If you are unsure how to proceed, please contact support@patterson-consulting.net and let us know the name and vendor for any File Defragragmentation program you are using as well as the Operating System in use.
Warning: The built-in defragmentation program provided with Windows Vista or Windows 7 does not provide any mechanism to exclude files from the defragmentation process. If you are using this Operating System, you may receive frequent requests to re-activate your software. The only known workaround is to disable the built-in defragmentation program and implement a third-party application instead. Those who can activate on-line should see little interruption due to the re-activation request.
Update: We have made adjustments to our licensing component to reduce the chance of file defragmentation causing your license to require re-activation. Contact support if you are still experiencing issues with licensing.